I got zipfits last spring and love them. I used a custom footbed in them for the rest of the season, and did not have my hotronics footbeds in because the temps were warm for the rest of my season. Want to put my hotronics foot beds in for cold days this season. My old liners had a slit in the heel near the sole that I could run the hotronics cable out. My zipfits appear to have some place for a slit in that same spot, but there is currently no hole that goes from inside to outside the liner (pic above). I am leery of taking a knife to the zipfits for fear of leaking cork material etc. any idea if you can slit them in that spot, or am I going to ruin the liner?