Yes I know the 1208 as it was hard to adjust my then hf rig to not overdrive the transverter on ssb, when it could be fine on cw. My 1208 did best with only 2 watts drive on ssb. The stock ubitx has no transmit drive adjustment. I would add a transmit drive pot before the PA. You may need someone to listen to your signal to get the level correct, unless you have a peak power meter.
The 2m transverter from tentec has a leveling loop, it is much better at managing drive level. But sure having a qrp rig with a known 20m output level is useful here.
For now, assemble your ubitx and enjoy it. I suggest avoiding bands above 20m until you have added mods to improve spurious.
Curt
