yeah, it's more like... if it's a nonstandard port, mark it as such, and connect much less frequently....ie: only one nonstandard port connection per day... with a doubling backoffs on failure, and random time to attempt.   this would allow nonstandard ports to exist.   any web server can handle an extra 10k requests evenly spread out through the day, so no risk of ddos.   if this seems to work, and it's useful, and it doesn't turn into a mosh pit on testnet, the levels can be slowly raised to 10 nonstandard peers per day, or whatever.