You’re welcome. It takes some practice, and sometimes it takes a few approaches to an apk, because in some cases removing some services or receivers can prevent the app from starting at all. But it’s worth the effort, because you end up with an app that’s stripped of all or nearly all undresired background activity, especially all those “crashlytics” or “campaign-tracking” services permanently uploading data wherever they want and eating battery. Same way you can also remove ads.
The most important thing to remove is
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
as this is the permission that allows launching app’s services when the Android App Support starts.
Another permission you can try to remove is permission to run services.
Then look for receivers like e.g.
<receiver android:name=".receiver.Starter">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
</intent-filter>
</receiver>
as these are the actual “event watchers” autostarting some of the app’s functions in the background.
Lastly, check for services referring to undesired functions like crashlytics or uploading of app usage statistics and remove them, too.
Maybe initially it looks complicated, but after one or two apks it becomes a routine job.