I took a few minutes to compare parts via various online parts fiche sources between the AXYS SKS and the AXYS PRO RMK and I can see where the confusion stems from.
When you pull up the AXYS SKS it gives part # 5139237 for the SKS with no other sleds using that #, which to me seemed strange that they would invest that much money tooling for one part for one sled model.
So I looked up the case number for the AXYS PRO RMK and it is # 1333255, checked the cross reference and it lists the AXYS SKS, curious right?
I checked the right fender and both the RMK and the SKS use the same right fender (with the deep well for the dropped chain case).
So my suspicion is it does indeed use the RMK components and the 3" will fit as long as you go to the RMK 7 tooth, 3" pitch drivers. (To be extra safe I'd pull a few measurements first, but) I'm pretty confident from my half hour sorting thru online fiche that it will go on with the same clearance as on the RMK.
Like the PRO RIDE chassis the the AXYS cooler does not protrude into the tunnel any more than the non-cooled close off does. My $0.02 FWIW