Surround

Hi There!
i am a new one here
my question (or idea):
i want to make the mpc (XL) to be a multichannel audio device to get surround sound.

My idea is :
use
send 1 for front speaker
send 2 for back speaker
send 3 for subwoofer

Track must be routed to any unused output (eg usb 24)
return 1 routed to out 1/2
return 2 routed to out 3/4
return 3 routed to out 5

(working)

now i want to automate this by EnvelopeFollowers / LFO / Crossfaders
problems:
Crossfaders:
i can set CF left to send 1 100% - 0 %
and CF right to send 2 0% - 100 %
fo fare fine:)
but the 16 Crossfaders cannot be controlled by anything else but the ribbonstripe
so if send 1 and send 2 of a track is panned front/back this way and all other too just different amounts possible)
or :
i can use ENVfols or LFOs - but than i need 2 slots for modulation
1. modulates Send 1 100%-0%
2.modulates Send 2 0%-100%

but i canot automate it further - for reducing or increasing the "flying" of the sound.

Am i wrong?
is there another way to do this? (maybe in future)
is it possible to set one destination "true" and another "inverted" inside the same module?
is it possible to set an additional automation (lfo modulates EnvFol?
is it possible to modulate the 16 crossfaders each different - by MidiCC?