Yes, this is possible. A MIXING can contain several groupings of instrument’s as you may require, because unlike Performance Mode, in a MIXING you can freely assign both the transmit and receive channels.
You can use one of the COPY functions to copy Performances to Mixing setups by directing the data to Parts 1-4, 5-8, 9-12, or 13-16 as necessary to accomplish your goal.
While each copied Part can bring along its INS EFFECT (you can choose to bring these along when you copy), but all the Parts will share the Reverb, Chorus, Master Effect and Master EQ as these are all SYSTEM settings.
Press [MIXING] to enter your Song or Pattern’s tone generator settings
Press [F3] COPY
Press [SF3] PERFORM
Select the USER 1 or 2 Bank, find the Performance you wish to COPY, Mark the attributes you want to copy from this Performance; set the target Part 1-4.
Rinse and repeat for the second Performance targeting Parts 5-8
Then again for 9-12.