A couple of heavier guys have run Dragons in the SIMA masters class. It’s the the Nordam direct drive engine but with a clutch, which is pretty much the Leopard bottom end with a special head. No relation to the X30 that I can see.
Not a lot of low end, but when SIMA ran the high speed track configurations the Dragons were untouchable, even with a substantial weight penalty. I think it would be dominating in road racing. TaG USA recognizes it as an option for “IAME only classes” like the IAME cup. But other than club racing at SIMA, I haven’t seen or heard of it being used anywhere in North America.