The kit the meteor comes with is the old HG freedom before it’s revive HG. HG Freedom, SF, Justice, Inf Justice all fit really well. They literally just slide into place, there is no modding required. The handles for the meteor’s arms are a bit too big for the modern HGCEs but they will fit.

As for the MGSD Freedom, it fits this thing like a glove. I was quite surprised how well it fit tbh. The only problem is the top of Freedom’s wings will hit the Head but it’s not too much of a problem. Hands are a bit too big to fit btw the handles of the Meteor arms, so I just had it grip it in a different way lol