Own effects for both main and aux?

Hi everyone,
We have replaced our analog desk with Qu-5 and are very pleased. We use it in our band rehearsals, to drive vocals and some bass drum into PA. At the same time we want to use it for stereo recording of the whole band (16 channels) into USB-A and we have set up the Mix7 for that purpose.
We are using effects slots 1 and 2 for the main mix and would like to add own, independent effects also into the recording Mix7 by using the remaining free effects slots 3 and 4.
We have tried to assign the slots into Mix7, but the input for those effects (3 and 4) appear to always follow the Main Mix fader.
Is there a way around this limitation? Many thanks in advance!

You should in all 4 FX send mixes be able to switch each channel from Post to Pre (Main Fader).