You can setup custom sensitivity:
In HKCU\SOFTWARE\miHoYo\Genshin Impact
In prop GENERAL_DATA_h2389025596 stored json with config:
Something like this:
mouseSensitivity is doing it's job, but i have no clue how mouseSenseIndex works.
{
"deviceUUID": "",
"userLocalDataVersionId": "0.0.1",
"deviceLanguageType": 1,
"deviceVoiceLanguageType": 2,
"selectedServerName": "os_euro",
"localLevelIndex": 0,
"deviceID": "",
"targetUID": "",
"curAccountName": "",
"uiSaveData": "{\"currWindowResolutionIndex\":0}",
"inputData": "{\"mouseSensitivity\":0.001,\"joypadSenseIndex\":0,\"joypadFocusSenseIndex\":0,\"joypadInvertCameraX\":false,\"joypadInvertCameraY\":false,\"joypadInvertFocusCameraX\":false,\"joypadInvertFocusCameraY\":false,\"mouseSenseIndex\":0,\"mouseFocusSenseIndex\":0,\"touchpadSenseIndex\":0,\"touchpadFocusSenseIndex\":0,\"lastJoypadDefaultScale\":1.0,\"lastJoypadFocusScale\":1.0,\"lastPCDefaultScale\":0.8999999761581421,\"lastPCFocusScale\":1.2000000476837159,\"lastTouchDefaultScale\":1.0,\"lastTouchFcousScale\":1.0,\"switchWalkRunByBtn\":true}",
"graphicsData": "{\"currentVolatielGrade\":-1,\"customVolatileGrades\":[{\"key\":1,\"value\":6},{\"key\":2,\"value\":15},{\"key\":3,\"value\":3},{\"key\":4,\"value\":4},{\"key\":5,\"value\":3},{\"key\":6,\"value\":5},{\"key\":7,\"value\":1},{\"key\":8,\"value\":3},{\"key\":9,\"value\":1}]}",
"miniMapConfig": 1,
"enableCameraSlope": false,
"completionPkg": false,
"onlyPlayWithPSPlayer": false,
"resinNotification": true,
"exploreNotification": true,
"volumeGlobal": 10,
"volumeSFX": 10,
"volumeMusic": 10,
"volumeVoice": 10,
"motionBlur": false,
"gyroAiming": false,
"monthlyCardShown": false
}