Can’t see it working. “standard” kart pipes are designed to have as wide a power band as possible and shifter pipes are designed to work in a narrower rpm range which is usable due to the tranny.
I guess on shifters with powervalve plugs, it wouldn’t benefit much…if it was on an actual bike where the rpm ranges were wider, then maybe. Would be interesting to see an ICC pipe on a MX engine on a dyno…