So, I communicated with a few of my email audiophile friends, and someone has heard both the Ypsilon VPS-100 phono stage and the FM223 phono linearizer, and his comments are that the FM223 was too analytical and too noisy; he thought the Ypsilon to be very detailed, but with slightly diminished dynamics. . .
In the meantime, I heeded the suggestion by @lewm and got a SOTA relfex clamp, and it does improve the sound of the Rega P8 markedly so, even moreso than the spindle weight that I was using. The clamp really cleans up the sound coming from the vinyl, and it is a very noticeable improvment for anyone with a Rega TT!