Thought you might like a peek at my set-up for low level light latensification.
On the far wall of my darkroom, I have a piece of peg-board with a row of hooks spaced for 6 rolls of 120/220 film. I use 12 common paper clamps, the 6 upper clamps and the 6 hook ends are dabbed with glow paint. The 6 lower clamps have 6 ounce fishing weights attached to keep the film from curling and swinging around.
When I'm latensifying 8x20 film, I peg in some extra hooks (which have a dab of glow paint on the ends) at the appropriate places on the peg-board. To locate the clamp on the film end without biting into the emulsion, I made a simple jig out of mat board (again, with glow paint at the appropriate places) that guides the clamp to the middle of the film end and limits it to a 1/8 inch "bite".
At the opposite end of the darkroom, 11 feet away, I put a common Kodak 5-1/2 inch safelight with a #3 filter and a 7.5 watt bulb. A variety of "waterhouse stops" limit the light output according to film speed. The one to the side has a few strips of tape to "adjust" the light output. I haven't got around to making a proper one yet, it's been working ok for the past 5 years....
I've adjusted the light output "stops" for a consistent 16 minute latensification period for all of the films that I use. My darkroom is in the basement. During the day I darken the outer rooms so I can get in and out while the film is being latensified.
That's how I do it...