actually all midimix configs (scroll down) use scripts with the same name with partly different content.

HOW TO : portable or parallel Config

Portable : make a portable installation via installer and
import the config file in the started portable instance

Parallel Config : Create a folder and start REAPER with Parameter -cfgfile "insert the directory path here"
import the config in the started parallel config instance

i will make a config that has all in..the assigning of midimessages to those scripts will vary per config then.

for all configs it is necessary to set the MIDIMix as First (Number One) as input midi device and set it as input
for midi and control and as output as the scripts use stuffmidimessage. in windows mine would set nearly like this

the configs should include that already , but.. never knows what borks a config

midimix_3_knobs_4_fx_recarm_noosc (NO OSC)
midimix_3_knobs_3_fx_recarmforsynths (NO OSC)
midimix_3_knobs_recarm_mutes_items_on_track (NO OSC)
a testversion with switchable recarm_scripts

midimix_3_knobs_4_fx (OSC)
midimix_3_knobs_4_fx_recarm_ktb (OSC)

and remember : If you are not a daw pro after learning -beep- reaper then, you know, there's something wrong with you"