Hi,
I installed manually using the pre built package from syncthing web page
Alt-F does the same, it just downloads and installs the syncthing pre-built arm binary from them (the only Alt-F exception), and doing some adjustments.
You can see what is done looking at /usr/lib/ipkg/info/syncthing.postinst, and what is done to integrate it with Alt-F looking at /etc/init.d/S81syncthing (the check_user call is defined at /etc/init.d/common and creates directories and users)
and doing the updates from the syncthing web ui. It's been working fine from some time now. What's the advantage to use the version from alt-f repos?
None for you, which is not afraid using the command line. But Alt-F was created mostly for ms-windows users, that mostly only know how to hit the "Install, Accept, Next, Next,...Launch" buttons"
Just checked and its now on version 1.18.0, Linux (32-bit ARM) "Fermium Flea" Build 2021-06-21
I never bothered updating to a new version because its webUI clearly shows an "Update" button.