Not auto-sufficient

Hi!
I truly love your app, it is fantastic, otherwise I would not be here writing right now. Thank you very much indeed to let it open source and free :)

I am using a Nexus 5 but all my contacts are syncronized through DAVdroid, your app works and let me do everything without any problems, but only since there is active and working the horrible counterpart app "People" from Google. When I disable google-contacts-aka-People, your-contacts-app works only since I try to add/modify a contact, then it seems to be unable to manage the DAVdroid window and crashes in an istant.
I think that this should be due to the fact that the app can add/modify a contact, but when the contacts database is on DAVdroid your-contacts-app uses the People-google-contacts-app to change the contacts database synced by DAVdroid.
The problem is that I there is no purpose in using contacts if I still have enabled the google contacts app, it would be as having two apps that do exactly the same, a waste...

Can you reproduce this bug? Do you think there could be a solution? (please help me disable People )
Thank you very much