^^^^ Very much this. Any little note that aids memory/instills confidence is worthwhile. I used to have tunes that I’d have a mental block with, which only got worse as the section approached. I’d just write a few chords down on the set list that I could quickly look at for reassurance.
Pitch pipes for me too, although I found them rubbish for ages (they were fine, it was my ears that were at fault). TBH, once I could discern pitch, I tuned to records (E or A usually) and then harmonics from there.
Sadly this has contributed to its undoing.
I used to go in there lots, when I worked uptown. Hobgoblin were just up the street a bit, on the opposite side.