David Vestal wrote a good article about latensification in Darkroom and Creative Camera Techniques a few years back. His approach was to hank a whole roll some distance from green safelight such as is used for development by inspection for something like 15 minutes. I worked on a contraption to do that while you worked on other things. It was a wheel shaped thing about a yard across with a puller-inner worked by a crank. A green LED was to be at the center, reflecting off a very small polished hehisphere. This reflection is practically a point source. One would load it in the dark, cover the entrance, set a time, turn on the LED and have a cup of coffee or make some prints while it was cooking. Matbe I'll get around to finishing it someday.