I'm not a Rodinal expert, just a casual user. There was a thread last year named; Making The Most of Rodinal. Link takes time to load.
I'm using the guidelines in the following article and adjusting from recommended starting points.
I only use roll film with Rodinal.
My best negatives which still need tweaks have been with FP4, EI 64, Rodinal 1:75, 11 min, 20c, light conditions winter Oklahoma sun, (4) to (5) inversions the first 20 seconds. (4) gentle inversions each 60s. My developing tank is steel with a (4) or (5) 120 capacity. I load (1) 120 reel and use a 35mm reel for as a spacer. One inversion provides complete mixing of the solution. If I had a smaller tank my agitation would be more frequent to achieve the same results.
My Rodinal is at least 4/5 years old and recently turned a darker honey from light honey tint.