Another three cents:
As a qrp-operator I do not yet grasp the concept of qrp-frequencies. The fun is the qso in the free world of the bands, not in a fenced reservation zone. IMHO.
If there is a problem with congestion, I favour spreading activations across the band(s) when possible hardware-wise. It increases the challenge for chasers (espcially fun when chasing with qrp).
Sooner or later someone will spot the activator on 7026 or 7018 (at the time you can safely activate an EU-summit during daylight there are no qrp-condx for US - but of course we need to look for US more and more on the higher bands even without awards for DX-qsos). Then it comes to bedlam and that is IMHO the bigger topic (sorry for drift): The initial pileup after a spot will sound somewhat discouraging for someone just testing his CW-proficiency and runs qrp to a compromised antenna - which makes it extremely difficult to control a pile-up.
Even with a better signal it is sometimes difficult to keep to a tight rhythm to sustain “order”. But SOTA should be fun not a challenge like a Clipperton-pileup which would reduce the motivation to activate, the number of activators and they time the deal with the callers on the qrg.
Maybe some tips should be gathered here to smoothen the stress, like “working down the bands” (20 to 30 to 40) and starting somewhere in the band to have a few minutes without spot-pileup, escaping from a uncontrollable pileup to another qrg etc.
The rest can only be recommendations, like better chasing with LP/qrp to reduce QRM for the other listeners, behaving as one would want to have it being on the other side - and maybe even naming a few very bad offenders.
Personally IÂ´m reluctant about real “up”-split as it would significantly increase the bandwith used for SOTA activations. Split only works effectively if callers really spread, other than all calling exactly 1 up (which “only” clears the activators qrg from some/most qrm but would cause an unworkable zerobeat pileup like skimmer pileups of “clickers” in contests). A “1up”-pileup in reality quickly eats 2khz and more (nobody will have a ragchew between both qrgs…).
P.S. About more frequently naming the SOTA-ref: It is really difficult to send it AFTER your call as then there are some/many automatically calling again so the ref drowns in qrm. What recently works was to comfirm the report of a caller with “tu fm DM/TH-… de DL8MBS” thus mentioning the ref before the call.