Have you tried a timer dial? I used one for a day just to see what it was like, and thought it a better solution than a chart.
Progressive stop-interval test strips were a PITA, and I went back to using seconds.
For burns and dodges I either used the difference in seconds between stops tick marks or for very simple cases did the burn live, to burn 1.5 stops over 3.0 stops: set the timer to 4.5 stops; place the burning card; start the timer; remove the card when the timer had wound down to 3.0 stops.
When I see a print that needs some corrections, I think f stops. I guess it's a carryover from camera practice. Sometimes I even make adjustments that way, but more often I change the time. It's pretty easy to convert in your head and at least get in the ball park. (A third of a stop is 25 percent more or 20 percent less; two-thirds is 60 percent more or 36 percent less.)
Then I bought the RH Designs timer. (not intended as a plug) I discovered that this timer has a feature where after determining the two exposure times for the hard and soft exposures, the timer will compute the resultant grade.
?does it do that? How is it done and is it useful, you still have to determine the two exposure times?
Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand