Replying to Modifying iso 9523 boots to work with GripWalk or iso 5355

I have Scarpa Freedom RS boots with the changeable soles. One is an iso 9523 touring boot with pin insert. The other are iso 5355 but of course without pin inserts. So are I've had Look Pivot 18s on one pair of skis and Fritschi Tectons on another and have been switching the soles each time switching skis. Now I've finally gotten a Cast Touring system, but without pin inserts in my iso 5355 soles, this doesn't work. I know I can get the boot conversion from Cast but I'm not really willing to spend another 200 just for that. In addition I would still have to change the soles each time, and I believe it doesn't even work with the peculiar soles of the Scarpa Freedom. So to my question:

Could I modify the iso 9523 soles to work with the GripWalk or iso 5355 AFD plates offered with the Pivot Cast system?
Since the Fritschi only relies on the pins, I don't really care about the soles (they're also very worn out anyway).
Logically, it seems like I could sand off some of the rubber on the touring soles to reach the GripWalk standard, but maybe I misunderstood the differences.

Some photos attached