dnanstad
I see now you sold the Thiels and kept the PL amp, this amp has a peaking high frequency that starts at 10k, only a 2ohm load flattens it out (green trace) a speaker that seems subdued in this area or one that has a 2ohm load in this area will be a good match to look for.
https://www.stereophile.com/images/1214PLDPIfig01.jpg
Maybe look at Martin Logans ESL’s that have active (200w) bass like the Montis, because ML’s do have a 2ohm load in the HF this will nullify the PL’s peak and the ML having an active bass means the PL won’t have to do it which will be it’s weak area. The more I think of it, this could be a match made in heaven, but not for party levels as you have limited wattage from the PL.
https://www.stereophile.com/images/912Montisfig1.jpg
Cheers George