What a great question. It sent me back into the code to verify the whole path.
Severity is locked into the rule, so the agent can't demote a blocking finding just to finish. It can propose a suppression, but now it can't approve its own exception. I verified that for both blocking severity levels.
The useful rule I added is that the agent whose work is being gated can't also be the final authority on whether the suppression gate applies. You improved the system. Thank you, Kartik
Treating must-fix as a stop-gate the same way as block is the design decision that makes this actually work, because otherwise the agent just declares victory and walks. The health check with no timeout hanging forever is a great catch, and the fact it forced named tests for the public functions is what turns "I fixed it" into something verifiable. Do you gate on a fixed severity list, or can the agent negotiate a finding down to a suggestion, which feels like it could reopen the same escape hatch?