After playing some Skyrim and being inspired, I implemented doing scripted events without level sequences using splines to move around regular actors and MoveToLocation node in Behavior trees for NPC characters and setup actors which are just actors with scripted event interfaces, referenced actors, and particular logic to that event, much like director blueprints for event tracks in Sequencer. Those setup actors are placed near the scripted event with blueprint interface functions to wire the referenced actors to make the scripted event happen.
If you still need level sequences to work in a world partition level, then check my bug report. 5.1 Level Sequence cannot play in a world partition level