I believe the whole playerbase disagree openly with the vision that "the dungeons are not supposed to be at max spawn all the time".
No group of players ever say "Oh, let us head to Toth and hope it is mid or low spawn so we can do it", "God, let us hope the Vestibules are weak, or else we will need to give up!", "Please, let us pray that the Ship was recently raided so we do not find too challenging foes."
From the playerbase we do expect to find a dungeon near the cap of its supposed spawn because it is what we are planning to face. Not being able to finish a dungeon because it is too strong is a failure both for us (who had not our fun) and for everyone else (because the next prepared group will find the place at low spawn because of the trial and failure).
It makes no sense to try to push a mentality that a dungeon max level is around 14, so, you, lvl 9, should go there hoping to find it at low spawn and will have an adequate challenge and reward, but, if it by miracle is too high, turn your back and plan another thing or you will gonna die.
It is bad time allotment running across the server searching for an available dungeon.
I can understand the idea of tiying the spawn to the server player population, but if the regular server population with the regular server playstile is not enough to allow that the dungeons are usually at a regular spawn (i.e., at least near the expected challenge), the rate of growing seems inadequate.
Also: this makes the whole server design strange. If it is intended that Tejeda is constantly at a lvl 8 challenge rating, for instance, it should be near Vallaki. "Recently" the Village of Barovia suffered a push up in challenge to reflect it's nature of "no beginner area". What is the sense in making all the spawn slow growing in a way that you push dow the challenge rating of every dungeon for levels down?