I've even had dreams about missing the time and screwing it up. haha.
Me too!! But getting less stressed about it as the months roll by...
Just for clarification on the original question is this thread, this is what FF says: https://www.fertilityfriend.com/Faqs/Same-time-or-three-hours-of-sleep.html
I've experimented with mine and found that generally even if I have less than 3 hours (often have to get up and pee in the early hours) or if I take it at a diff time give or take a couple of hours, it doesn't really make much difference to my chart. It still shows a clear rise for ov - which is the important bit about charting.
And I don't use the temp adjuster because there doesn't seem to be any pattern where my temps are higher the later I get up or lower earlier, often it's the opposite, so I reckon the temp adjuster would make my chart less accurate rather than more! (Personally I don't like the idea of the temp adjuster. Surely its data must be based on an "average" person, but very few of us are average so it could make your data really inaccurate? But, that's just me. I "believe" in facts and empirical data and don't like fiddling around with it! (Tried to find a smilie for "nerd" but is the nearest and will have to do!))