I am also completing my UCD 60. I have a Cline regulator as well, but will try running the Saito 91 GK first without it. I thnk a simple test will be to hold the UCD vertically and running the engine at different RPM's. There will be varying tank pressures when the airplane is in the air, but I don't think it will be very critical. I built an onboard optically switched glow ignitor for mine. This was supposed to be my winter flyer but did not have the time to complete it then, but should have some fun with it when I don't want to risk my 2 giant scale Edge 540T ies on windy days.
I would have loved to get a Saito 100 fro mine, but already had the 91 Golden Knight. Please let me know how it flew with the tank on the CG.