Odroid XU-4 // System change to arm64?

Originally i install in the past an arm32 version on my XU4 - i think, it is the only image for i can download on syncloud. Can I update my device easily to arm64? Makes it sense? Thx for reply!

The easiest way is to flash new arm64 image.
This is the image to use https://github.com/syncloud/image/releases/download/22.09/syncloud-odroid-xu3and4-22.09.img.xz

If you want to preserve your app settings make sure you update to latest platform from Settings - Updates first as it gives you cross-platform backups.
Make sure you are using external storage (Settings - Storage).
Then backup every app.

Then if you are on sd card I would use another one for a new image to flesh, boot, activate the same external storage, install your app, restore their backups.