Looks like the Foldback (FLB) send can be used same as the EFF send...so that means you can feed both Left and Right sides of the Reverb unit with each of those.
Basically...treat those two knobs as your AUX1 and AUX2 sends...there doesn't aapear toi be any difference between them.
Now, even though the reverb unit is coming back in stereo, you DON'T have send from both AUX1 & 2 for every channel.
IOW...you have electric guitar on CH1 use AUX1 to send to the reverb unit. Then you have
acoustic guitar on CH2 use AUX2 to send to the reverb unit.
You CAN use AUX1 as your send for everything...BUT...it really depends how your reverb unit processes the L/R inputs.
Does it do its own mixing internally to give a stereo output regardless if you just send to L or R input...?
Or...does it need a L/R stereo input to give you a L/R stereo output.
Every box is different.
Now let's assume the reverb does its own summing and creates a L/R stereo output even with one input. So ten you might ask, why not just use AUX1 for all your sends....???...because you don't want to overload the one AUX bus.
So I usually split between two for a given stereo processor.
Though also some FX units might behave differently at their stereo outputs depending if they get a single input either on the L or the R channel.
IOW...the stereo output might sound a bit different for each single input....check it out.
That's why I like to use two AUX sends per stereo FX unit.
Of course...with only two AUX sends and only a stereo FX return you may want to split things up if you have more than one FX unit, though you will then have to find a way to submix both units for the single stereo input/return...OR...you can use a spare channel(s) for other FX returns if you have them.
Makes sense...?
Go take two aspirin and call me in the morning.
