diff --git a/app/src/test/java/eu/darken/capod/common/datastore/DataStoreMigrationCompatTest.kt b/app/src/test/java/eu/darken/capod/common/datastore/DataStoreMigrationCompatTest.kt
index d7908f0e..b16fd5ed 100644
--- a/app/src/test/java/eu/darken/capod/common/datastore/DataStoreMigrationCompatTest.kt
+++ b/app/src/test/java/eu/darken/capod/common/datastore/DataStoreMigrationCompatTest.kt
@@ -9,6 +9,7 @@ import eu.darken.capod.main.core.MonitorMode
 import eu.darken.capod.pods.core.PodDevice
 import eu.darken.capod.profiles.core.AppleDeviceProfile
 import eu.darken.capod.profiles.core.DeviceProfilesContainer
+import eu.darken.capod.common.upgrade.core.FossUpgrade
 import eu.darken.capod.reaction.core.autoconnect.AutoConnectCondition
 import io.kotest.matchers.shouldBe
 import kotlinx.serialization.SerialName
@@ -16,6 +17,7 @@ import kotlinx.serialization.json.Json
 import kotlinx.serialization.serializer
 import org.junit.jupiter.api.Test
 import testhelpers.BaseTest
+import java.time.Instant
 
 /**
  * Tests that verify @SerialName values match @Json(name=...) values,
@@ -68,6 +70,9 @@ class DataStoreMigrationCompatTest : BaseTest() {
     @Test
     fun `SerialName matches Json name - PodDevice Model`() = verifyEnumSerialNameParity<PodDevice.Model>()
 
+    @Test
+    fun `SerialName matches Json name - FossUpgrade Reason`() = verifyEnumSerialNameParity<FossUpgrade.Reason>()
+
     @Test
     fun `Moshi-serialized ThemeMode string is readable by kotlinx`() {
         // Moshi stores enums as JSON strings like: "theme.mode.dark"
@@ -103,6 +108,36 @@ class DataStoreMigrationCompatTest : BaseTest() {
         }
     }
 
+    @Test
+    fun `Moshi-serialized ThemeStyle string is readable by kotlinx`() {
+        val moshiOutput = "\"theme.style.materialyou\""
+        val result = json.decodeFromString(serializer<ThemeStyle>(), moshiOutput)
+        result shouldBe ThemeStyle.MATERIAL_YOU
+    }
+
+    @Test
+    fun `Moshi-serialized ThemeColor string is readable by kotlinx`() {
+        val moshiOutput = "\"theme.color.green\""
+        val result = json.decodeFromString(serializer<ThemeColor>(), moshiOutput)
+        result shouldBe ThemeColor.GREEN
+    }
+
+    @Test
+    fun `Moshi-serialized AutoConnectCondition string is readable by kotlinx`() {
+        val moshiOutput = "\"autoconnect.condition.seen\""
+        val result = json.decodeFromString(serializer<AutoConnectCondition>(), moshiOutput)
+        result shouldBe AutoConnectCondition.WHEN_SEEN
+    }
+
+    @Test
+    fun `Moshi-serialized FossUpgrade JSON is readable by kotlinx`() {
+        // Moshi with JavaInstantAdapter serializes Instant as epoch millis Long
+        val moshiJson = """{"upgradedAt":1709553600000,"reason":"foss.upgrade.reason.donated"}"""
+        val result = json.decodeFromString(serializer<FossUpgrade>(), moshiJson)
+        result.upgradedAt shouldBe Instant.ofEpochMilli(1709553600000)
+        result.reason shouldBe FossUpgrade.Reason.DONATED
+    }
+
     @Test
     fun `Moshi-serialized DeviceProfilesContainer JSON is readable by kotlinx`() {
         // This is what Moshi would produce for a container with one Apple profile
diff --git a/app/src/test/java/eu/darken/capod/common/datastore/DataStoreValueSerializationTest.kt b/app/src/test/java/eu/darken/capod/common/datastore/DataStoreValueSerializationTest.kt
index 4acf322b..8721c0a0 100644
--- a/app/src/test/java/eu/darken/capod/common/datastore/DataStoreValueSerializationTest.kt
+++ b/app/src/test/java/eu/darken/capod/common/datastore/DataStoreValueSerializationTest.kt
@@ -1,13 +1,20 @@
 package eu.darken.capod.common.datastore
 
 import androidx.datastore.preferences.core.PreferenceDataStoreFactory
+import eu.darken.capod.common.bluetooth.ScannerMode
 import eu.darken.capod.common.serialization.ByteArrayBase64Serializer
+import eu.darken.capod.common.serialization.InstantEpochMillisSerializer
+import eu.darken.capod.common.theming.ThemeColor
 import eu.darken.capod.common.theming.ThemeMode
+import eu.darken.capod.common.theming.ThemeStyle
+import eu.darken.capod.common.upgrade.core.FossUpgrade
+import eu.darken.capod.main.core.MonitorMode
 import kotlinx.serialization.builtins.nullable
 import eu.darken.capod.pods.core.PodDevice
 import eu.darken.capod.profiles.core.AppleDeviceProfile
 import eu.darken.capod.profiles.core.DeviceProfile
 import eu.darken.capod.profiles.core.DeviceProfilesContainer
+import eu.darken.capod.reaction.core.autoconnect.AutoConnectCondition
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.matchers.shouldBe
 import kotlinx.serialization.json.Json
@@ -16,6 +23,7 @@ import org.junit.jupiter.api.io.TempDir
 import testhelpers.BaseTest
 import testhelpers.coroutine.runTest2
 import java.io.File
+import java.time.Instant
 import eu.darken.capod.common.datastore.value
 
 class DataStoreValueSerializationTest : BaseTest() {
@@ -143,6 +151,97 @@ class DataStoreValueSerializationTest : BaseTest() {
         result!!.toList() shouldBe testBytes.toList()
     }
 
+    @Test
+    fun `enum round-trip - ThemeStyle`() = runTest2 {
+        val ds = createDataStore()
+        val pref = ds.createValue("style", ThemeStyle.DEFAULT, json)
+
+        ThemeStyle.entries.forEach { style ->
+            pref.value(style)
+            pref.value() shouldBe style
+        }
+    }
+
+    @Test
+    fun `enum round-trip - ThemeColor`() = runTest2 {
+        val ds = createDataStore()
+        val pref = ds.createValue("color", ThemeColor.BLUE, json)
+
+        ThemeColor.entries.forEach { color ->
+            pref.value(color)
+            pref.value() shouldBe color
+        }
+    }
+
+    @Test
+    fun `enum round-trip - MonitorMode`() = runTest2 {
+        val ds = createDataStore()
+        val pref = ds.createValue("monitor", MonitorMode.MANUAL, json)
+
+        MonitorMode.entries.forEach { mode ->
+            pref.value(mode)
+            pref.value() shouldBe mode
+        }
+    }
+
+    @Test
+    fun `enum round-trip - ScannerMode`() = runTest2 {
+        val ds = createDataStore()
+        val pref = ds.createValue("scanner", ScannerMode.LOW_POWER, json)
+
+        ScannerMode.entries.forEach { mode ->
+            pref.value(mode)
+            pref.value() shouldBe mode
+        }
+    }
+
+    @Test
+    fun `enum round-trip - AutoConnectCondition`() = runTest2 {
+        val ds = createDataStore()
+        val pref = ds.createValue("autoconnect", AutoConnectCondition.WHEN_SEEN, json)
+
+        AutoConnectCondition.entries.forEach { condition ->
+            pref.value(condition)
+            pref.value() shouldBe condition
+        }
+    }
+
+    @Test
+    fun `data class round-trip - FossUpgrade nullable`() = runTest2 {
+        val ds = createDataStore()
+        val pref = ds.createValue<FossUpgrade?>("upgrade", null, json)
+
+        pref.value() shouldBe null
+
+        val upgrade = FossUpgrade(
+            upgradedAt = Instant.ofEpochMilli(1709553600000),
+            reason = FossUpgrade.Reason.DONATED,
+        )
+        pref.value(upgrade)
+        val result = pref.value()
+
+        result!!.upgradedAt shouldBe Instant.ofEpochMilli(1709553600000)
+        result.reason shouldBe FossUpgrade.Reason.DONATED
+    }
+
+    @Test
+    fun `InstantEpochMillisSerializer round-trip`() {
+        val instant = Instant.ofEpochMilli(1709553600000)
+        val serialized = json.encodeToString(InstantEpochMillisSerializer, instant)
+        serialized shouldBe "1709553600000"
+        val deserialized = json.decodeFromString(InstantEpochMillisSerializer, serialized)
+        deserialized shouldBe instant
+    }
+
+    @Test
+    fun `InstantEpochMillisSerializer - epoch zero`() {
+        val instant = Instant.EPOCH
+        val serialized = json.encodeToString(InstantEpochMillisSerializer, instant)
+        serialized shouldBe "0"
+        val deserialized = json.decodeFromString(InstantEpochMillisSerializer, serialized)
+        deserialized shouldBe instant
+    }
+
     @Test
     fun `sealed interface polymorphic - DeviceProfile`() = runTest2 {
         val ds = createDataStore()