What does Dual Position Air do?
What does solo air do?
Do they all have dual position with 30mm travel adjust?

Trying to decipher the difference between this and this from the rather garbled product descriptions.

Also, whats the difference between 15mm maxle and 15mm axle, and will either work with my Hope ProII hub?

this might help

Do they all have dual position with 30mm travel adjust?

No

[EDIT] – in your defence On One’s product descriptions are unclear to say the least, since they refer to two totally different types of Rockshox forks .

I’d call them if I were you. It looks like a bit too much copying and pasting of product information has gone on so who knows what you’re ordering.

Dual Position Air is like Fox’s TALAS i.e. you can adjust the amount of travel
Solo Air is where the positive and negative air spring are adjusted simultaneously, whereas previous Revs have separate valves for tweaking the two air chambers (this was confusingly called Dual Air)

Dual position = Adjustable travel (AKA TALAS)
Dual air is a standard air fork with 2 air chambers (+air and -air) for tenability.
Solo air is the newer simpler version with just 1 air chamber.

AFAIK 15mm axle and 15mm Maxle is the same thing on any Rockshox. And yes, Hope Pro 2 can be adjusted very easily.