I disagree, I have to say, re: "meat grinder".
I think it's much like CoC here as
@MGibster described. In that, in a lot of situations, so long as you actually have guns and get the drop on enemies, you can be extremely effective. Especially if PCs have the stats to support that. It can be quite deadly but like, not excessively so. PCs have a relatively decent amount of HP. If you do stupid things yeah you may die but like, it usually requires you to do something stupid for it to be a "meat grinder". This opinion may be influenced by the adventures I've played in and/or the fact that I am naturally extremely cautious and well-prepared though! The DM did say one adventure that we'd all be dead and/or dying at least three times I hadn't told us not to do certain things lol.
I've played a lot of games of Mothership, too, and I've never seen "a panic chain" or the like. I don't think that's easily possible. Yes, one character panicking will increase Stress but my experience is that PCs will usually have very different stress levels - like one guy will be on 15, and another will be on like, 5, so it's unlikely the guy in 5 will panic. There are definitely volatile combinations (a bunch of soldiers and an android is asking for trouble lol) but most of the panics I've seen have been just one PC getting hit by it.
The only rules modification we've made is that we made armour decrease by one each time it's used rather than just going away entirely, but I'm not even sure that is a rules modification!