I found that less than 10 minutes residence time with cold (-40c) ethanol leaves too much target compounds behind. Also, a FFE or other thin film continuous flow evaporator design is far superior to a roto.
OP, LN2 or CO2 in a counter flow coil with the extraction solvent flowing through the opposite direction would be my next move. A chiller pumping through an immersion coil would work ok as well