Well it's only the collapsible version that has the sloped cam. The LTM one modeled after the original has a proper secondary helicoid.
Since they made it a collapsible Elmar type design something had to give. Nikon got around this by making their tiny LTM 35mm lenses not collapsible.
The lens always screws in the same amount for all bodies as far as I can see. I assume that where the rangefinder pick-up roller is exactly was never specified closely for LTM.
The bodies that worked are - (my Friends) IIIc, my II (since sold), a Canon L1, VI-L and P.
The one that didn't was the Canon 7. I found the Canon 7 picky with some other lenses too. I have tried 3 Canon 7 bodies from various people and it seems to be more or less consistent. So I assume Canon did something to the LTM specification there - perhaps to make allowances for their 50/.95 - who knows!