It would kill the dynamics of the amp, use the loop volume instead. The problem with a PPIMV is that it affects the negative feedback. At low volume settings, it turns most amps into a mushy, fuzzy mess.... IMO they are only good for knocking a few DB's off a non-master type amp.
I used to use a Scumback DBL attenuator with an early Splawn Quickrod I used to own to knock a few DB's. I found that a much better solution. I don't need one with the 2021 Competition I own.