I know that a project can be modded to have hubstacks, but can an m1 also?
Yes it can 
Awesome! Just one more reason that i should get one then.
It isn’t recommended by one drop to hubstack the m1.
Drat. I just got my M1 and i love it lol. I was telling myself, “Over the summer, this baby is getting hubstacks.” But i think I will take your advice on this once 
why is that? does it affect play?
I asked this when I was buying an m1 and docrobot said it would wobble.
You may wind up breaking the nut which really aren’t made to be replaced (or even taken out) like the ones in the projects.
oh ok. that’s good to know, thanks.
that would be cool. m1 with hubstacks.
Its been done.
Yeah, it would be nice to put h/s on an m1. But i could not take a chance on crazing up the play on it. It is one of the best if not the best YO-YO’S that i have.
tickle it
I believe the newer M1s have circular nuts instead of hex, so they’re a no go for hub-stacks.