Well I gave it a shot but nothing is ever easy 
Foiled again I'm afraid.
Docker image maptiler/tileserver-gl failed with:
"no matching manifest for linux/arm/v7 in the manifest list entries"
I neglected to tell you I was installing on RPi4 running Buster 32-bit.
Per GitHub issue: https://github.com/maptiler/tileserver-gl/issues/49 I would need to upgrade to 64-bit Bullseye to make it work. Don't believe that is an exercise I can afford to undertake at the moment. I'm afraid I'd break something in my current setup.
I suppose I could backup and try on a copy and see if the upgraded image is running my apps properly....
