I remember many years ago some mentions that some version of the G3 would be feasible as a replacement in Blizzard cards, but given the value of the Blizzards I guess it's not worth the risk and apparently noone has seriously tried.
I've lost interest in the Classic PPC stuff after getting a Pegasos G3, an A1200 for old games and programs is great but for more recent apps / productivity it's a waste.