I tried one 35mm roll. 17minutes at 20degC. But I don't remember where the time came from- I must have estimated it from some other times. Contrast was quite high, and shadow detail was disappointing, but that might have had something to do with my metering. Lighting was very overcast. Grain was not particularly tamed, but I haven't tried the film with any other developer, so my perception of grain might not be very relevant. Also, of course, overdevelopment is not good for grain.
So for 35mm SFX, I would recommend maybe 13minutes or even less. I suspect that PMK is completely finished at 17minutes anyway.