No, sorry to confuse you, I've not used Rodinal/RO9 with Foma films, I preferred 3 to 100 with Tmax 100 @ 50EI and Agfa APX100 at box speed, I think I'd start with 1 to 50 with Fomapan 200 @ 50EI.
Essentially when I do my tests usually on 35mm film I bracket a test shot metering at box speed, then stop down a stop, for the second exposure, a half stop for the third at metered aperture, 4th open up half a stop, 5th to a full stop and sixth is a stop and a half, then in the dark I open the camera and remove the exposed portion of film develop those frames for my expected time, once dried evaluate. Then I can make adjustments do test prints of the most suitable negatives, however I've 50+ years of printing some of that commercially so I can read a negative.
Ian