The Devs have said before they cannot do this because some PCs do not handle the LAA flag well. Putting LAA on would be highly frustrating to those users.
Most mod players are quite aware of it now though, so I don't think its much trouble to make it a requirement for your mod Tobi.
But, doesn't Steam provide options on what runs? It wouldn't be a matter of replacing the .exe, just adding another one, or an optional flag, or whatever is needed.
I'm thinking of Ashes of the Singularity and how it requires that you pick to play with DX 11 or DX 12 when launching the game. If it can do that, I would think having the choice for LAA is possible as well.