I sometimes use Rodinal, for Fomapan 400,and I have never found the grain objectional, in fact it you get a nice grain with Fomapan, but not an all over grain, it will mainly show up in the sky if burn.t in,I always used 1/50, and have used box speed with it, also the 400 @250, especialy when using the camera's meter, with my trusty Weston meters on MF I will often use 400, and I personally find it needs that bit extra, and develop between 15 and 18 minutes@20, which I find suits the way I like my negatives to be, 2 years ago, for most of my photographic life I developed everything in Rodinal, never used anything else, the tonality of Fomapan in Rodinal can be quite beautiful, and last year, covid lockdown and all that, I experimented with different developers due to to much time on my hands, and liked ID11, but I am gradually going back to Rodinal to get the tones I like