So.. I guess crossposter is somewhat working now, and I'm more-or-less happy with the way it turned out. It's far from perfect and I still have to write Discord integration for it, but in case anyone wants to check it out, feel free to do so: https://github.com/hatkidchan/mastoposter

For now I'm using quite hacky way to listen for current-user-only posts, I'll work on that in future. Also I'm planning to add support for threads and filters and whatnot in future

pic: random image to test that it still works lol