Is it dumb to do that based on principle? I really think it might help me sleep better at night.
I would confirm with the L herself that it will protect you financially. Assuming that it does, I think that you have the compromise that you have been looking for. You protect yourself and your kids. And you can sleep better at night not having filed for D. It will allow your H to make decisions about his career and future and he can always proceed with the D. You may get some backlash from H, but we are only focusing on what M wants!