I hope no one gets offended by my opinion or method, but I just wanted to share what I'm doing in the hopes it will help.
I "tray" develop my 4x5 in Glad storage trays that will easily handle a 5x7. I give 1-3 minutes initial agitation by lifting 1 side of the tray per second for that time. Then during the rest of the time, I lift 1 side of the tray 1 times every 10 seconds, which for me it works as a general rule.
Here's a low quality scan showing what can be done this way.
Copy of iunsub.jpg
Ultimately, though, it comes down to what YOU are most comfortable doing.
If you wish to inspect during development, use an incredibly dim green light for very short durations. Any even mildly bright light or any long times will fog the film.