The original logic stopped decrypting any INITIAL packets after the
first. The Firefox/cloudflare pcaps actually show that the server
replies with a QUIC INITAL packet containing just ACK frames and no
CRYPTO frames. Only the second QUIC INITIAL packet from the server
then contains the CRYPTO frames.
There's no good reason to stop decryption attempts, either we succeed
down the road and then stop, or we fail and raise analyzer violations.