@PINE64 Sounds really interesting, I'm going to wait a bit more to change my phone.

Operating wise, it's going to be : Who ever is going to port on it ? Will you sell it with an operating system ?

@Luksus
I wouldn't be surprise there is a remaining bit of armhf code somewhere.(How were you able to install it ??? on arm64 phone)

I suggest to remove the app and search manually for any ubsync and Nextcloud or Owncloud related, then delete them.
like sudo find / -iname "ubsync"