Where does userconfig.txt come in the boot sequence?
I believe that config.txt is loaded and then cmdline.txt, does userconfig.txt come in between?
My reason for asking is because Volumio updates could write new versions of config and cmdline and because my Preamp setup uses the rPI UART connection to display song title and artist data I have to manually remove the section console=serial0,115200 from cmdline.txt. If userconfig was loaded between I thought I might be able to run a script to remove the console section before cmdline was run.
Thanks
Bumped, as no replies in 17 days.
Is there some other way of removing the serial0 section before cmdline.txt is implemented?
Does it have to there for other hardware configurations?
If I recall correctly, the file sequence is config.txt, userconfig.txt, cmdline.txt.
You could even add an alternative comdline.txt to your userconfig.txt.
For example create your new cmdline.txt file, in this example I called it wheaten.txt. Then you can add
cmdline wheaten.txt to the userconfig.txt.
In this case it doesn’t matter what the cmdline.txt is doing.
BUT BE AWARE:
You might run into other issues when mandatory changes are published in the cmdline.txt. You rPi might fail after an update and you prob. won’t remember it was due to this change. Neither will we!!!.
It’s a much smarter and safer practice to remember adding your line back to the cmdline.txt after an update.
Thanks for the detailed reply.
The editing of cmdline.txt is no big deal, my issue is that I have to remember to physically remove the UART connection from the PI to Preamp Controller, before a V’ update, reboot the PI, then replace the UART.
All a bit of a faff.
If I don’t complete all this then the Controller gets confused and then nothing works until it is rebooted and re-configured.
An even bigger faff!
That is up to you what is the bigger faff 
A confused controller or non working Volumio.
I would go for the confusing part.