I did the taking independence quest recently and at the end i got a message that Preston is now available as a companion. However, now he's back in the sanctuary and I'm trapped with his infamous settlement quests. Although, this hasn't affected the minutemen quest line, as I have got old guns from him, any other attempt to interact with him will only give me settlement quests ad infinitum. The same thing happens when you happen to turn over a completed settlement quest, more quests whether you like it or not.

I looked up one way to bypass them is to back out of the conversation immediately when you turn over a quest before he starts talking again.

Its not like I eagerly wish to recruit him as a companion but its frustrating when you have a potential companion you cannot possibly recruit. Sometimes I wonder if all this is a bug or if the devs had some purpose behind it.

Do you have 1.3 installed? Since that last patch, Preston has stopped giving me MM radiant quests, ad infinitum. The MM quests received from Radio Freedom has also dried up almost completely for me.