Nikon iTTL remotes (Radio Popper etc) on older equipment

I frequently use my F5 and SB-28 strobes when shooting weddings (yeah, 35mm film, so shoot me!). I like the idea of taking the strobe off the camera and triggering the TTL function wirelessly. Radio Popper makes some of these devices, as does a Chinese company called Pixel Knight. Their compatibility listings however are all digi-centric (although I've seen mention of the F6). As for strobes, the only ones listed are the current generation, SB-600/800/900 et al.

Has anyone tested these devices for backward compatibility?