Happy to see folks trying to get T21 to work on single phase. We've done this on a couple of test rigs and can't really tell a performance/efficiency difference between T21 and S21.
Yet the T21 is considerably cheaper, and comes with a Bigger PSU.
One issue I've encountered is that after you change the PSU and power bars, there doesn't seem to be an easy way to cover the power bars etc, since T21 does not come with a PSU cover piece.