I am a bit overkill when it comes to midi. Been using since the 80’s and thought I could figure anything out, but I feel like a total noob right now. I couldn’t find this on the forums, nor could I find a tutorial using AI on Google, so here goes… Some of the info below is for reference only. The main need is how to sync toggle states from the MC4 P scene selection to the MC8 P stomp toggles on Page 1. Sorry if TL;DR but this is killing me…
I have an MC3, MC4 Pro, MC8 Pro and QC Mini. Please don’t roll your eyes and ask why. Overkill, remember? 
The chain is the same; MC3>>>MC4 P>>>MC8 P>>>QC Mini. The QC Mini is set on my board so I don’t use it’s buttons (cuz they’re a P.I.T.A. - dual switch nightmare). The Midi Channels are 4, 3, 2, 1 respectively (MC3 to QC). The MC3, on press, controls tap (A), tuner (B) and toggles Scene selection (1-4 & 5-8) on the MC4 P. On Long Press Release it toggles to Page 2 on the MC8 to toggle between Poles 2 & 4 (button A) and Decay (Smooth / Fast) on the Moog Filter (think Jerry Garcia Mutron III). That works the way I want…for now 
. The MC4 P controls scenes. I have it set to Toggle Reset Groups 2 for all 8 scenes, though I can’t figure out if I can set it to reset the Scene if I toggle a preset (stomp) on MC8 P, but that is not as important (yet) as the main need. The MC4 P is directly controlling the scenes in the QC Mini midi thur the MC8 P, but the MC8 P isn’t syncing the toggle states. Example: Scene A1 on QC = Button A, G & H on, all others off. Scene A2 = Button B, G & H on, etc. How do I get the MC8 P to reflect those toggle states? Also, as mentioned (‘yet’), Am I able to set the MC4 P to engage the Scene with a single press and reengage the same scene by pressing again? I need this to reset the scene if I decide to toggle another stomp on/off on the MC8 P in that scene. Example. Scene A1’s button A = OD, G=Chorus & H=Delay. I might want to add a pitch and Env Filter, which i will just manually do, but want to reset the scene by pressing Scene one again. Right now it will toggle between Pos 1 and 2, with 2 being the actual scene engage. I couldn’t figure out how to set it so it didn’t need to ‘toggle’ so that I could just press each scene to engage/reset the scene. Right now, if I push say Scene 1 (button A), position 2 shows Caps w/ Blue color with bar. If i push it again, it shows lower case with light blue and no bar but does nothing. I just want one ‘instance?’ where it stays ‘on’ and resets the scene.
Not sure if this is clear enough, and I know it’s a lot to digest. I am hoping someone with more intelligents (and patience) can give me a line item explanation of how to program each device…