Most of the sound on your Hohner, if I’m not mistaken, comes up through the keyboard. The aluminum may have some affect on the sound but probably does not mute it noticeably.
By the way, the unevenness of keys referred to in that discussion is usually very easy to fix by inserting a small blade between keys and pushing them apart or together to even them out. Or by depressing adjacent keys and pushing the offending key one way or the other. I realized this after wasting time taking several apart to adjust the keys. This works for apartment dwellers as well as for those of us who own large estates.