The seal on mine broke a couple of years ago, but before that I had it. I never knew not to wear it at night and never noticed a difference. However, both my visor and the pinlock sheet were not tinted which might make a difference. The only probably I've had with visibility is when using polarized sunglasses. They make it hard for me to see the LCD screen.
Way back in the day, 1973 TBE, there was no Pinlock, I was riding my CL450 in all types of weather due to a non-running car. CA had recently instituted mandatory helmet laws and I had a third or fourth-hand Bell with a shield. To keep the fog off, I'd work up a lather of hand soap, smear it onto the inside the shield, let it sit for a few minutes, then wipe it off with a dry cloth. The now-coated shield remained fog free for several days, then it would be time to re-coat it.
I never did put the pinlock in my euro helmets. Just didn’t get around to it, and now it’s warm enough that I don’t really need them.
... sometimes it is just easier to crack the helmet visor open a smidge.
I had never heard of Pinlock until this thread. Had to look it up.
I reckon the use of a helmet shield pinlock is a non-issue in Arizona unless one rides often in the more northern region.
Dry air is helpful.