@jtsteph
I just discovered, they already support the Loupdeck officially, as well as several other interfaces.
I don't use the original Software, so I can't compare. You can copy/move buttons between positions and pages. But only one at a time. But there is an export/import function, which can be used as a workaround to move whole pages.
The page up/down buttons can be moved and removed freely, and there is an internal button function to jump straight to a specific page.
The plugin link I gave you, was probably misinterpreted by me. It is a Loupdeck plugin which enables the Loup software to use the companion functionality (both softwares have to be running). There is a Streamdeck version as well. This way you use the original software for programming as usual, but implement companion buttons programmed in companion.
The plugins use the remote interface / API of companion, which enables remote control by several protocols, like OSC, ArtNet, etc. This way you can easily trigger buttons from a different device (e.g. a computer running Isadora, sending OSC to companion, triggering a button which shuts the light via Home Assistant or ESP). There even is a Web remote interface which emulates the physical interface in a remote web browser.
The companion open source community is very active and as it is used a lot in professional live media/ event productions, there already is a long list of of modules (called connections) with specific support for software and hardware devices.
I personally use the raspberry version with a pi 4b which is connected headless to the network, as a multi device remote interface. With a PoE+ HAT you even don't need a PSU anymore, or you go wireless with a Powerbank. (this isn't mine, but there are several examples for companion pi).