For most of my detailed cutting I've been using generic #11 craft knife blades and it seems the "wear curve" on them is rather aggressive to start with then kind of goes flat.
Like, a new blade goes through leather like butter but that lasts for maybe 4-5 decently sized cuts before it starts needing multiple swipes and then at some point it almost feels like the leather is bumpy or grainy where the blade isn't cutting through denser sections.
I don't want to be too wasteful nor do I want to be forever changing blades - how long do you tend to go between changes?
(I don't leather craft, but I do plenty of other craft and engineering things.) I used to be pretty stingy about changing blades until I bought a 100 pack. Now I happily change the blade when I feel it getting dull or when I'm starting a new project. I'm ok with having to go over a cut a second time or so, but when the blade is dull enough it's making the cut less clean, it's definitely time to change.