The fluid output and item consumption rates are nigh unlimited. The bottleneck is the transfer of biofuel from the internal buffer to the output tank, which occurs at a rate of 1mB/t. There is a fine difference in that if you let the reactor backlog fuel in its output tank you can drain it immediately. A single bioreactor can keep 7 MFR generators supplied, but you probably want one extra reactor over the 1:7 ratio so you can build a little excess.
I only tested this in regular Infinity Evolved, but MFR itself has no numerical configs to change any relevant properties.
