I still haven't done the incision. Did you fabricate the piece from a similar hard foam? I still haven't gotten around to making a 3d part that connects the left sidewall and extends it to fill the gap left from the new foot room.
Looks like you and I are at the same juncture. I haven't committed on how I'm going to cut the carpet, because it's a single shooter. Did you notice the entire carpet lining spans the whole left of the cabin front-to-back?

Not an easy replacement! I did go as far as cutting some 'x' incisions so the pegs of the dead pedal would fit through. I'm currently using a packing foam block, which is a bit softer than the stock foam. For now, I've also left the sidewall notch unaccounted for, as this was a proof of concept. Am really enjoying the extra leg room on long trips.
I think for my final approach, I will cut into the oem foam block instead. It'll already have the side-notch provisioned!