Which Syncthing Fork should one use after the project's handover?

The two developers have eventually joined hands, so there is only one actively developed version of Syncthing-Fork right now, with releases available both on F-Droid and Google Play. I’m not sure if the Google Play release has currently any limitations in comparison to the F-Droid one.

If you want to avoid the controversies though, there is also Syncthing Tray with its experimental Android builds, and lastly you can run Syncthing from the command line inside Termux.