I had some available time over the holidays and made a lot of progress on this project. I ended up starting fresh and reusing/refactoring a bit of the original project initialization code in the GitHub esp32-spotify-remote project. With the exception of the certificate being out of date, the code all seemed to work up to initializing the device and authenticating with Spotify.
For my project, I refactored this code to eliminate dead code from other projects, allow the header files to better be reused, and to generally position it to support a bigger more expansive code base. I also updated the dependencies to use the latest versions which seems to be working fine. Using that as a starting point, my working version is currently calling the Spotify API, displaying a landscape UI with two display modes with one including the album art, album title, song time, and artists, refreshes include retry logic and loads Spotify data using the ESP32's native multitasking abilities (currently pinned to one of the two cores), and supports next, skip, and pause.
I still have a bit more to do, but the GitHub project definitely helped... just don't think of it is a compile and load type of thing like the Weather app is. However, if you were like me, using the now bricked Spotify Car Thing as a desktop Spotify companion, the Color Kit Grande is everything you need to get a replacement running. I actually built two to use in various rooms. The advantage of using this kit over some of the efforts to bring the Car Thing back to life is that the Car Thing doesn't seem to have the hardware necessary to stand alone without running companion desktop software. This is fine if that is the only place Spotify will be running, but if you run Spotify in a variety of settings, don't want need/want software running on the desktop, and/or you want something portable, then the Color Kit Grande offers a lot.