Ok I just did a quick test and can confirm that all these buttons switch between Global/Per Brush but the tooltip only says “Inherit”, that’s a weird explanation for what they do, or at least it is to me not being a native english speaker hehe.
Anyway I’m glad that’s possible now, and personally I’d suggest to make them Per Brush by default (Unchecked), and keep the Collapse toggle unchecked for brushes that are tipically used to add detail on the surface, like Crease, Pinch or even the Snake Hook
Leave Collapse off for Crease
And keep it on for Sculpt Draw
Also, the ability to change the detail size slider per Brush can be very useful!