Another reason I don't run my starter cable through the cut off. It's death by a thousand cuts killing them regardless of momentary rating. Sometimes they will weld themselves in the on position and the switch won't work at all.

A test that only requires a wrench, hook the battery up to the downstream/starter side of the cut off and test it. Turn the key. If it does the same action as when going through the switch, you can scratch it off the list.