Game not launching via steam

Hello all,
today I downloaded the BeamMP multiplayer mod. After the first few rounds I can definitely say that the mod works very well, but I noticed one thing that can’t be considered a bug, but gave me something to worry about. When you start the game via the multiplayer launcher, the game is still shown as “off” on Steam. Is that not a crack? Can’t Steam (Valve) punish you for that? What I mean by that is, you bought the original game on Steam, but you use an .exe modified by third-party developers, which then allows you to use the game without Steam. Or am I wrong? I’m also active in other forums that don’t deal with BeamNG, where even a modification to the .exe of the game is called “dangerous”, for which you can possibly, and with a lot of bad luck, get a Steam exclusion. But now you even have a launcher that apparently starts its own .exe, which is not recognised by Steam. Isn’t that against the rules?

Otherwise, it’s really great what you’ve done, keep it up!

Best regards,