ReVibe II - one of my favourite reverbs for post - is a performance hog. Each instance is always "surround under the hood".
Having a multi-mono instance on a 5.0 aux (to follow the input panning) results in 5x the load of a normal 5.0 instance.
Even a mono instance calculates all surround legs (see parameters), only to output a mono downmix.
Please update for proper scaling, maybe giving a true mono-only instance.
Also, updating the code for better performance in general would be great, it does impact CPU on my system and other studios I work at. (native, DSP card load also very high!)
TEST SESSION with 5x Multimono and 25x true-Surround included for comparison