well it is because its expensive and takes a lot of effort

Its like 10k to do the H22A swap, and would be the same amount if not more for the B18C. As you know the B20A is a bastard engine that is different to everything else, so you need custom mounts etc etc etc

As for anyone doing it, dunno i havent heard of any here. Someone in the US is bound to have done it.

If you were gonna mod the gen3 i would just boost it *shrug*