For me, a Bodyguard “Max” wouldn’t be of much interest. I like my M&P Bodyguard quite a bit for what it is, but if it were any bigger than it is, I wouldn’t really have a use for it. I’m not one who feels that the .380 cartridge is ineffective, as I’ve investigated plenty of shootings over the years that proves otherwise. I do find it to be less effective than a 9mm however, and when you start adding width to the Bodyguard, you are entering territory where I believe the 9mm would be a better mousetrap.
To sum it up, the Bodyguard is an excellent pocket pistol. One of the best in fact. It makes a poor belt gun in my opinion, and a thicker version would necessitate carrying on a belt in a holster where an even bigger, more powerful pistol would be a better choice.