Never had any notching issues as you speak of (if i'm understanding correctly).
Never heard it mentioned before either (i don't think).
Even if it did, after tensioning those notched would move......AND after that they will notch abit nonetheless, once tensioned.
I've never really known...
FWIW, the casters Gamma sells are quite nice. With a brake, they roll really smooth etc.
Yes, they are spendy but I knew they'd fit and work well. They do.
I initially was on the same $$ saving path but it seemed like a PITA as I wanted brakes too. YMMV.