Very good, but you are being polite!
I shall be a bit blunt.
- The science (& Rob Watts) are against such a practice! it yields no objectively measurable benedit, indeed the opposite is true. Meaning in most cases it is detrimental.
- Regarding RFI, an LPS is noisy. Since it has a ground wire, the chances of ground loop noise is much higher.
- As far as I know, TT2 has super capacitors inside, so even a battery pack won't be any better.
I know it is Fun to tweak this and that, and god knows, I am guilty of that as hell. But rest assured, Rob Watts is a thorough designer. If an LPS was beneficial, he would have put one inside!
Universally, those DAC manufacturers that compete on Noise figures, have adapted SMPS, against LPS.