Uhh, does the model 13 have a modular panel? IIRC, they don't. Also, manufacturing modular panel and modular port are very different and the knowledge transfer cannot be that big. The port for example has a looser tolerance since they aren't really that visible most of the time. So being snug but not flush is good enough. I can imagine the panel doesn't have that luxury. Stability issue, that I can agree. But then again, I'll give them the benefit of the doubt since they must handle additional assumptions that cannot be made on other laptops. Namely, modular GPU. Writing a firmware with that new assumption could be a PITA.