OpenNetworkConnection() supports overriding the proxy to use for connecting. However when v2 connection is attempted and it fails a v1 connection is tried without that proxy.
Store the override proxy in CNode and pass it to CConnman::m_reconnections to be used for v1 retries.
This is a serious flaw I have overlooked when the override proxy is used for private broadcast connections. Reported in https://www.erisian.com.au/bitcoin-core-dev/log-2026-05-18.html#l-234