I forgot the guy has me on ignore. Someone please be so kind and repost my post as screenshot or something, so that the guy can get the information he seeks.
Yes it does.
It can very easily be tested in the psykhanium, since we have damage numbers there.
I just spanked a Crusher for 117 at no stacks and for 186 at 3 stacks of T4 Thrust.
That’s a 59% increase (186/117 = 1.59).
Blessings that say “up to x%” in their description, actually mean “x% per stack”.
Has been this way for ever.
1 year ago, i wrote a huge bug report that included almost every single faulty description.
It got acknowledged, but of course the descriptions have not been fixed.