Yea, that’s a challenging part for sure, one that I still deal with.
It can be done, but you need to configure the sync jobs “just so”. Send only from the phone, don’t sync deletions, etc.
In the past I’ve setup a master folder on my phone and used subfolders for “upload only” Syncthing shares. Then wherever I put a file on my phone it gets synced to the appropriate folder on my server.






Yea, I thought about the page file adjustments, but didn’t feel like getting up and looking at a machine because I couldn’t remember exactly what the screens were, haha.
Plus Windows has gotten so much better. With 95, Win2k, etc, manually setting it really made a difference - seemsnto make much less difference today. Though it could help OP - worth trying anyway.