Happy case: server response fits in the 3600-byte budget
Server
Client
ClientHello
1200 bytes (padded)
ServerHello, Cert, CertVerify, Finished
~1 KiB < 3600-byte budget
client Finished + 1-RTT request
handshake complete
address validated
3x cap lifted
1-RTT response (application data)
client has the data