We are going to have to respectfully disagree on the subject of Martin, I do think the podcast itself basically explicitly states he's fat, which does stand out seeing as we don't get a lot of canon character appearance descriptors.
My actual fanon design gripe in this area is Michael. Why is he always a pipe-cleaner thin twink in his early 20s? Based on the timeline we get in canon he was almost certainly middle aged when he died, I could accept that he died in his 30s in a pinch.
I also just can't picture him as having that sort of build at any age. The way he is described by other characters (Sasha introduces him as "a large man with long, blond hair", Helen focusing on his height then saying that his face was "round and unthreatening", but that she found him intimidating anyway) suggests his human form is physically imposing in a way that isn't just due to his height. That could be interpreted in any number of ways, obviously, but I don't think the fanon design quite works. I wouldn't personally describe a man who was tall but incredibly thin the way Sasha and Helen do. I also just think it is fun if his human form is very visually distinct from his "Distorted" form.
older micheal who could throw me against a wall to give me a magic concussion just for fun….. wow you’ve opened my eyes thank you 🥴