You got it. I usually start with a determination of time-to-maximum black, then divide up evenly, but same difference. Basically, you are making an artificial, ideal interpositive.

Find time for filters from 00 to 4 (or whatever) so you have those as reference when you need them.

I've only ever done 9 steps as that is sufficient for my temperment, but from your previous posts, you sound like a stickler...