Ok! The main thing is that davdroid works very fine. You just found another customer to the app.
Just keep up the good work and thanks all your help you provided for me!
How often can DavDroid sync without severly impacting battery life? I ask because caldav on my iphone syncs very quickly (within 1 minute) but yet the default sync interval for caldav-sync is 6 hours.
Oh I think I see. It looks like with Android 7.1 the min sync interval is 15 min. Is this right?
Yes, that is the fastest interval that is allowed from Android - therefore its also the minimum that can be set in DAVdroid.