This is a patch, that forces game ignore checksum when starting and loading ironman game.

In other words, yes, it gives you the ability to get achievements with mods enabled. And not giving you ability to use game console or connect to servers with other checksum.

1. Download latest binary of patcher from releases (or build it if you know what you doing)
2. Unzip it in game directory (right click on game on steam > Manage > Browse local files)
3. Run universal-checksum-patcher.exe

Congrats, you're done! In case you see unsupported version error most likely Paradox broke something and all you can do is wait until I update patch. Most likely i'll update patch when I decide to play, so feel free to get needed byte code and modify source code (I'll merge your pull request if you decide to do that. Or create fork, I don't care)