Well I would keep the same dose regardless of PS, and keep your no-shoot high enough that you feel comfortable with that dose. So if you are ok with shooting 1.2 on a 200 PS, but are worried below that, I would make that your no-shoot (ok, maybe 190 or something).
If time is such that you can't retest past +12 if you get a lower PS & have to shoot right then, then you have a smaller dose that you shoot, the highest you are comfortable with, maybe 0.75 (assuming the PS is above the bottom-line no-shoot of 150).
When I'm saying try 0.75 on a 150 it's not that I think that's the highest safe dose. I think the dose will be too low. But I support gathering data to be sure. If you wanted to shoot 1.2 on a 160 I would be fine with that. He freefeeds, right? So I really doubt hypo is a big risk. Since you don't have a lot of data with doses like that on the lower PSs and I know you are gone most days at work and probably worried, that's why I would say you shoot a lower dose on the lower PS - for your own sanity. Then on the weekend, you shoot the higher dose and get some data to be sure it is safe.
What I see from the data that you have so far is that 1.4 is too high on any PS, and 1.2 is too low on any PS. I think 1.2 is good though as a "safe" dose - you can shoot that on a PS you feel comfortable with, and leave the house feeling good. He probably won't drift into high #s, and he probably won't hit greens. If you saw a PS between say 150 and 190, and felt comfortable shooting say 1u, that seems reasonable to me.
So long story short, LOL, how about:
PS 190+ - 1.2u
PS 150 - 190 - 1u
Great job today with the 1u! Nice PS, and nice blue mid-cycle. You can see there's room for improvement as well, and though this is fine for a safety dose, you can see it's safe to try 1.1 or 1.2 on this same PS next time. That's how you figure out the doses needed for the lower PSs, so great job getting really useful data today!
