My results so far are best described as mixed. I’ve developed a couple of rolls of 35mm FP4 Plus and two rolls of 120-format Arista.EDU Ultra 200 (Fomapan 200), and while I was expecting thickly “coloured” negs, what I got was visually not too different from a regular B&W negative. Following Pat Gainer’s suggestions, I bleached one of my negs with Farmer’s Reducer (basically a dilute solution of K3Fe(CN)6 and thiosulfate) to remove the silver image, and got a very faint stained image as a result. The negs are very sharp, though, and scan nicely. The FP4 Plus (example here) was developed for 7 mins at 22C, while the Fomapan 200 (example here) was developed for 8 mins at the same temperature.