Milo sounds like WC, and it is helpful to read descriptions of another kitty with similar hogging behaviour. WC needs everything nice to be his! I think spending one on one special time with him, when HB is busy out in the yard, is helping him feel more secure. And he also wants HB to like him, so he is slowly learning better manners and that if he shares he will still get his fair share. The breeder he came from was mainly focused on breeding F1s, and WC grew up sharing with a bottle raised Serval kitten the same size as his Mom, who was probably given more attention than the regular F6 kittens. So maybe that is why WC can have such a pushy attitude. HB often seems to look at him like he is wondering if he was raised by wolves.
I bought a hard plastic wind up mouse for my 2 and HB is completely fascinated by it. It isn’t a toy that makes him crazy playful, but he seems to be intrigued with how it works. He studies it picks it up, drops it, and just watches intently as it does it’s moving. And after 2 weeks he still spends a few minutes every day seeming like he is trying to figure it out. It is kind of a cool unpredictable toy, because it jams on a carpet, so it can sit there for hours doing nothing, and then when it gets bumped it suddenly starts moving around. The biggest recent hit is a $2 giant furry mouse rat on a long elastic cord on a wand. It looks and can be made to move so much like a real rat it gives me the creeps, but they both love it.