Yes, McMillan Racing who developed the Nemesis superkart chassis some years ago did some development with the TRX250’s. I believe the only real benefit was the counterbalance shaft and a six speed transmission. If I remember correctly there were transmission issues with regards to gear ratios not particularly suited to superkart racing. I think they developed and had gear sets made at a high price which offset the benefits to none and popularity never took off. There may have been other issues leading to it not becoming popular that I am not aware of.