Replying to 270 on - too wide stance

I can do 270 ons but I need to have a really wide jump and I carve my leg to the inside like crazy. (I go from a wide stance to almost a pizza and jump)

But for ride - ons and rails that have a narrow or rutted out jump, I'm screwed.

I noticed some people can do em without the really wide stance (french fries).  Is there any trick to doing them like this?

And when are you suppose to throw your spin, like practically on the jump (which is what I do) or after you feet leave the jump?

Thanks for the help.  Maybe this is a stupid question.