To avoid aliasing, an MTF of 0% would be the theoretical ideal, but in practical situations I don't think it's necessary to go that low. I think 10% MTF is sufficient to prevent aliasing. Using the formula for MTF of diffraction[*], I calculate that MTF drops to 10% for green light (550nm) at f/11 at 3.7 micron pixels. Using red light (750nm) I get 5 micron pixels. Both of these are slightly smaller than the 6 micron pixels in the EPICs.
Again, it's a question of what MTF you consider aliasing taken care of.
[*] 2/pi*(acos(f)-f.*sqrt(1-f.^2)) where f is 1/(w*f-number).