Serge, thanks for sharing this video, I’m also a Harbeth fan
I have a pair of 30.1 35th in the 2nd system, sitting distance 7’, very good match with my PrimaLuna Dialogue Two (now in the 3rd system with my older SF Cremonas).
The P3ESR are rated 83.5dB vs 85dB for the 30.1s but then your PL HP is 2x70W in UL vs my D2 which is 2x38W UL.
I guess it should be a pretty fine/musical combination and plenty power even in a bigger room.