Is it possible to remove an entity from a default group? Specifically, I would like to exclude a device tracker from the group.all_devices group. I realize that I could create a new group that excludes that entity, but I have a whole host of automations that reference group.all_devices, and I would like to avoid having to redo those automations if possible
Short answer - no.
The default groups are automatically populated. You’ll need to create your own group(s) and update your automations.
Dang, I was hoping I could adjust in customize or something. Ok thank you!
Just make a new group and do a find and replace in all your files. Super quick with notepad++.
Oh that will help! Good idea! Still have to do the Node Red automations 
but that will save a lot of time. Thanks!