ive also tried setting the secondary gi to “none” and , strangely it doesnt look significantly different, but, its also way noisier and actually takes almost double the time to render as that with the secondaries set to lightcache.
ahh just little blotches in the corners here and there.. in my own way i have resolved it. ive hidden the moving objects (they are quite small) calculated a flythrough lightcache for the scene, then unhidden the moving objects and rendered.. this , according to my tests, renders clean. and not noticeably differently, unless you are comparing side by side with a sharp eye. . Obviously the animated objects are only illuminated by direct light and one bounce of gi, but since most of the rays from those objects hit the static geometry which has the lightcache precomputed, they get almost a full lighting solution..
do you see any drawbacks to this solution apart from a lack of perfect physical correctness ..?