Most of the time I just minge servers and don't actually care to see errors, so when a server uses fastdl I'm able to set my downloaded preferences to map only. However, if they utilize workshop only then this won't work and I won't be able to connect without downloading the workshop items.
Also, I have a method for switch accounts without closing hl2.exe so the faster I can get back into the server the more clueless the admins are.