Way too much contrast to even consider it a start in calibrating the film, for use in normal pictorial applications, IMO. The way I see it, you shouldn't bother making EI adjustments at this point. Wait until you are a reasonable distance from "normal" contrast to tweak your EI, because the amount of contrast you put into a negative via development affects density even in the lower tones. At such high contrast, even your zone I placement can be affected. I'd chalk it up as a total loss and do the test again, doing everything the same as far as rating and your exposure sequence, but trying 10 minutes as a starting development time instead of 20.
P.S. It is not uncommon to have super contrasty negatives when first using a Jobo, if you are used to using a hand tank.
I must say that 20 minutes seems like a long time to be spinning in a Jobo...for any film and any developer (at least when normal contrast for testing is the aim). How did you arrive at this time?
It is also possible that you made a mistake in the mixing of the scratch developer, and/or perhaps a dilution mistake. Double check these factors as well.