Moving data to another (new) ncp-installation by davdroid?

Hi.
I would like to shutdown the nextcloud on my synology and use a new nextcloudplus (ncp) on a raspberry pi 3B+.

What is the best way to move my data from synology to the rpi (ncp)?

Is it possible to use my android device?
When i configure davdroid to the new nextcloud-adress, will it sync all the data or will it delete all the data because the ncp is stil empty?

I would prefer this method because it is much easier than exporting und importing all the stuff.

I exported (backupped) all my stuff and then tested it by myself but it did not work.

I recommend to ex- and import because thats really easy.