I've tried developing HP5+ and Acros together in Rodinal 1:50, and didn't like the results. Fuji recommends agitation twice every minute for Acros, and I stuck with that as the film has a lot of contrast to begin with. But HP5+ usually gets four inversions per minute, and with the reduced agitation it came out really flat and a tad underdeveloped---the Acros looked fine.(posted 8435 days ago)