I dont really have proof but i know ive seen if you start qbittorrent with just proxy no dht, in resource monitor(windows) say if you have set proxy to one on 127.0.0.1. It will show one connection to local host. If you set it to proxy + DHT you see the local host connection plus connection to all the DHT nodes/peers(whatever you call them, i think nodes is right). So i know for a fact that it doesnt disable it(anon mode does though but also does other things too). However im unsure why did doesnt fail use the proxy or fail/disable if the proxy doesnt support it.(It should do one of those if you ask me) Which is why if we automaticly disable it when a proxy that CANT support it then its a step closer not sure if you can have it check if the socks5 does have UDP or not(it could be either).