Is it possible to make a mod that lets you remove weapon mods? Does one already exist?

Yes but it would probably require NVSE and scripting options for it. I think there was mention in the nvse thread that someone was looking to work on it when the functions were added.

And I am looking on what it would take to provide the scripting functions to do the removal. No estimate on when that might be possible, however.

Good good and delicious stuff This is what I'm mostly waiting on before I start working on other things. I give many kudos for you and your teams work.