Too H-E-A-V-Y. Too complex with trying to adapt a computer system. Too expensive. By the time you engineer a PSRU, engine mount, fuel system, several propellers and all of the computer crap, you could have bought a brand new 912.
The 27” Desser tires are for 8” wheels. This is not the only time I have heard the 26” ultralight tires are prone to damage. I think it depends greatly on how heavy your plane is. If you have a 4-500 pound light plane you’d probably be okay. More than that, I would say go with the Airstreaks. If you have one of the fat-assed late model 900 pound planes, the “standard” heavy carcass tire would be better.