-I'm not sure if it's relevant, but my pickaxe skill was always 1-2 points above my mining skill when these data were collected and both supreme and rare pickaxes were around 90 ql. The supreme pickaxe also had the +10% gather rune which does not currently affect the max ql.
-Here's a post and graph by Retrograde from Retrograde in 12/29/2020 on gather imbue:
https://forum.wurmonline.com/index.php?/topic/181865-imbue-rework-formula/\