100% on the crew variability. On a PE flight to HND some months ago, one of the crew members gave everyone a welcome to the PE cabin and pointed out that the J lav in the galley forward from us is available for our use.

On a separate J flight to HND, one crew member tried to stop me, presumably, from using the most forward lav after I’d spent a decent amount of time in PE with friends. I was on my way back to my seat when one of of the Japanese-speaking crew started to tag me down, presumably to let me know that the forward-most lav was off-limits. As soon as I sat back in my seat they turned back around towards the lower J galley without saying a word 😅 Hey, very understandable, those windowed lavs are the best on offer!