Guidance (etc) and activities with a longer duration

[ProsecutorGodot]

I wouldn't allow that. Each instance of the spell is a different one.

Yeah, that's completely understandable and despite the fact that I might consider making an exception I do agree. In the event that you're making a check that is important enough to warrant this type of diligence I would expect a better buff to be available that doesn't require a ruling like this.

This is a purely mechanical viewing of the rules though, I find the narrative reasoning that PhoenixPhyre offers to also be persuasive.