Not much trial and error at all Alex. I already have my times using tubes and continuous agitation. I simply increased the times by 30%, 100%, 200% and 300%. Made 4 negatives of one scene of SBR 7 and another of SBR 10. Developed both to the 4 different adjusted times. Printed all of them on G2 AZO. Selected the time that works and adjust the rest of my times accordingly. The more I use minimal agitation the better the tweaking of the times got. Did not take me long at all (or that many negatives) to settle on a range of times. I use a dilution of 1:1:120 and my times are for negatives destined for AZO printing (they are quite dense).