I meant to update here:
I’ve tried 3 strings now on the singularity, it eventually ate through all of them: onedrop long cuts, yysl ammo, and kitty fat. I need to polish its response area with the dremel…
I recently bought some more C3 yoyos and I noticed all of them had a polish (or mask as @G2_Jake noted) around the response pads: atomic crash, remaster galaxy, omnitron. All of them! My respect for C3 just went up a few notches, they are already on fire with the amazing colorways…