I added another 6 readings to my already 100% calibration on the 1120 and it actually produced some definite, subtle, but perceptible improvements to both vocals and general clarity so it seems to me that RP does actually process readings made after the magical 100% - and make suitable amendments to the DSP profile if it hears something different?
This is unfortunately nothing more than a placebo effect. The filters are no longer adjusted or augmented past 100%, the difference between mid 90's and 100% isn't going to be audible and if it was you'd be listening in a very good room, from the perspective of someone mixing a a record or movie over time.
Your source material is widely different and inconsistent, it is the same for most of us. You also have to wrestle with the fact that you do not hear the same thing the same way twice. Your perception of audio fidelity will change without you knowing it, for a bunch of different biological reasons.
Studio engineers and musicians especially are repeating the same sound and tone over and over again, that's something that is crafted. It's also the reason why that engineers will not look at anything until they've tracked the drum recordings consistently, because if not then they can't be manipulated in post without being all over the place.
You can get slightly better room perfect runs, even before you start fiddling with speaker locations and crossovers / distances, but again it's not massively better. That's the only time I've noticed it ever being subtly and subjectively 'better'
Subjectively speaking, if you think it's better then take another 10,20,50 more readings - but it's completely in your head. I've got up and walked away from tuning instruments, recording and mixing because my brain would simply not work and then be fine as little as 20 mins later.