Carrying on from that thread:
MAMS AR: No, it wasn't just the recoil, the weight distribution and I guess middling weight really showed. I think it was when I was messing with Battle Change Core, and in the end I just had to stick with jiraiya blade or whatever else I settled on for other setups. (Oh also when I was doing what I'm writing about next, now I'm thinking about it!)
Compacts: I've mentioned my thoughts on this before: HMS is such a compact generation that a compact customization is not significantly more compact than the average HMS. There are large parts but even these are plastic. Add in Metal Change Core and Jiraiya Blade and compacts become very aggressive.
I played around with MCC as a defense tip, based on plastics, and fiddled with the idea of a less aggressive compact setup there but between the lack of suitable defensive ARs and the lack of grip or ability to add a significant amount of weight and stick to defensive parts, it just didn't work out.
In terms of defense in general while it's on my mind, GFC (UM) in particular just has so much grip and speed that even going for an HMS version of RF defense/anti attack using one of the other rubber tips seems impossible - GFC (UM) just throws them out of the stadium (and with GFC (UM) itself, the fact Samurai Blade and Circle Wide are both excellent parts with it and have really solid stamina means going for something more defensive on the same tip means you'll likely just get outspun). In general with that and most things I've tried the best result I've got is "comes down to wall saves, and don't blade on concrete". Perhaps there are options with RC's and parts I don't have (double god ring battle change core could work in theory, for example), but at the least I haven't found anything in the entire range of rubber HMS tips (rubber sharp core included).
That one particular combo I was messing around with using aero core is good enough that I'd like to know, especially given the fact beywiki needs an article on it.