Difficult to say. On the one hand you’re getting better SQ out of the DAC, which will mean better sound quality out of the 272 on a ‘ better in - better out’ basis
On the other hand, you could leave the DAC as is and improve the 272, resulting in an improved output based on the better power supply.
So which brings the most gain? Fortunately it seems like an easy question to answer simply by listening to both combinations. I would imagine that the result could be somewhat system related….for example how good or bad is the existing power supply to the 272 and DAC?
When we had a 272 we noticed a big improvement adding XPSDR on non digital sources (phono). So the PSU definitely greatly improved the preamp section of the 272.
The bare nDAC we’ve used with both a 272 and SuperUniti! Even without a PSU it has great detail resolution. You’ve already got an excellent digital transport.
I think with the bare 272 you’d find the pre the limiting factor with an nDAC/250 and so PSU could sit there, but only your ears will confirm.