I spent a lot of time experimenting with mine as it was winter and was doing several mods at the time.
I ran into the the same issue of my inner fairing contacting the speaker cone edge. I had already bought the Boom grills which make no difference as they contact the speaker cone also.
The Kappas cone diameter is a little larger than the stock speakers , also the frame is thicker is why I believe they make contact when mounted on the outside of the pods.
I ended up mounting them inside the pods , I build a gasket out of dense foam pipe insulation to seal the speakers rather than cutting the posts down as many claim they sound better mounted outside the pods. I did a side by side after I made the gasket and couldn't tell a difference.