So I did manage to get custom properties to show up in Sequencer tracks. They need certain UPROPERTY attributes to work. So I got that working, but not sure how to actually respond to changes to those properties. Currently we use PostEditChangeProperty but that doesn’t seem to be firing when Sequencer changes the property.
EDIT: Actually in hindsight it isn’t even changing the property on the actor. It shows a value in the sequencer track but when I look at the actor in the scene, the property isn’t being set at all. So maybe I need to do more to connect it.