"I routinely turn on a white light immediately after putting a print in the fixer. I have a 25W bulb in a Kodak "beehive" safelight enclosure right over the fixer tray. Why do it right away? Because I want to know I made a good print."(posted 8074 days ago)I use to wait at least two minutes before I turn on the light, just to be sure.
"I also turn on the light and look at test squares (not test strips) while they're in the stop bath."
I do the same thing.