The Sequencer Scripting plugin was the magic sauce to what I was trying to do. Once that was installed and combined with the Editor Utility Widget all the pieces started to fall into place. I now have a dozen static nodes set up as start/end transforms for a bunch of sequences, and I set up a button in the editor which when pressed will update all the transform keys in every track of every sequence file with new transform data. No more manually editing sequences!
Take a look at this post by PiranhaSauce who makes use of the Sequencer Scripting plugin to access the keys.
Here is a screenshot of the main node chain I made to access the keys in my sequences. It’s similar to what PiranhaSauce demonstrated in his code snippet.
Also, prior to Unreal 4.27.2 this Sequencer Scripting plugin only works in editor, it is not for runtime operations.
In Unreal versions 4.27.2 and later, the Sequencer Scripting plugin works at runtime, but accessing channels is still development only, so it won’t be accessible in shipping builds.