Question With MIDI CC 50 I can recall the different multi effect types, but what value recalls the different types of effects 

Using controller 50 will recall the 15 different types of effects . The values to be used are 1 to 15. They correspond clockwise to the effects shown on the front panel of the unit. On the M300: 1 is De-Ess, 2 is Compressor, Etc. On the M350: 1 is Comp, 2 is Hard Comp, Etc.