I've apparently run into a known bug where if you fast travel into the Institute with the above mission active and Power Armour equipped (possibly only with the targeting HUD), then you suddenly complete the "Talk to Z1" stage of the quest and are immediately ordered to clear out the Relay Room - except cannot use the elevator and the only NPCs there are Z1 and Father and you can't interact with them.

I spent more than half an hour running about trying to find where the fuck I was supposed to go since I didn't know there was a bug and now don't have any auto or quick saves from before I went down there - only an old save from 40 hours gameplay previous.

I tried loading the oldest autosave I had in the Institute and noclipped upto the relay room, from where I was able to complete the kill everyone part of the quest but then didn't get given anything further to do.

Is there anything more I can do other than load up an old-ass save and lose every hour of gameplay for the last month?