Julian, like you I shoot mainly film and prefer darkroom prints but I also shoot digital usually alongside but they rarely get printed. I can scan my negatives and my digital prints look very similar to the darkroom ones.
The point I was making is simple, that photographers who have had darkroom and enlarging experience tend to be able to get the best out of digital imaging quite easily. These filters presuppose that each film gives a different look and they can/will in some hands but with darkroom work much depends on the skill of the printer. Of course format is important a similar size print from a 35mm HP5 or Tri-X negative looks quite different to a print from a 5"x4" negative of the same films.
If you looked at my prints you'd find it extremely difficult to guess which images were shot on Delta or Fomapan 100, and Delta 400 or HP5, but then I don't shoot or 35mm very often. So it's a case of personal perspective.
Ian