This is disappointing. SyncThing is one of my reasons for picking Android over iPhone. I hope the author reconsidered. Would any GoFundMe-style donation goal make the hassle worthwhile?
When I migrated from Android to iPhone, syncthing was my main pain point. There is Möbius Sync, even though not open source, at least it’s an one-time small payment, which is fair considering the dev license cost. Unfortunately it’s not as reliable as the Android official app or the fork, I guess Apple is very strict with background processing, but hey it’s better than nothing.