notepad-plus-plus VS SyncTrayzor

No, actually Notepad++ has a dark mode, moreover you can install any theme, for example I like Dracula

I would use syncthing, which is open source at https://syncthing.net/.

After minimal setup, it just works(tm).

You have a normal directory in your filesystem, that is synced to the other peers (which you set up in the "minimal setup").

I have been using it for years, and it works well. It has no problems crossing os'es (i.e. windows -> linux, linux -> mac)

For windows I usually recommend https://github.com/canton7/SyncTrayzor, but vanilla syncthing works fine too (but don't try to mix them!)

for windows though, i have the "synctrayzor" version, which basically just meanas it runs with an icon in the bottom right corner. https://github.com/canton7/SyncTrayzor

I love it, plus there is a GUI wrapper for it: https://github.com/canton7/SyncTrayzor

1 - Install SyncThing on my main Windows PC (through SyncTrayzor so that it can start on windows startup)

Ah, something extremely similar affects SyncTrayzor on Windows too! https://github.com/canton7/SyncTrayzor/issues/760

If you are on Windows, are you using SyncTrayzor? Doesn't require setting up Syncthing as a service.

I have used Synctraysor for years, and absolutely love it. A little confusing at first, but once it's set up, it just works. I use it to sync 4 computers in 3 different locations. Never have to think about it. I live in Tennessee and have a second home in Illinois. They sync automatically so I neve have to think about it.

I have been using SyncThing via SyncTrayzor for over a decade on Windows. It is self-hosted, so I would suggest picking a high-capacity central point.