How do you set a secondary map for cutscenes in Unit Placer?

I’m not sure if anyone else has thought of this, but I was planning to use multiple maps for units to move around in for some of my cutscenes. However, I don’t know how to effectively change to a secondary map where the cutscene will take place.
What I’m trying to accomplish is the equivalent of the first cutscene in Sacred Stones. There, you see Erika and Seth moving through the Chapter 16 map which is Castle Renais, to a blank map outside the castle where the two encounter Valter before moving to The Fall of Renais map.
When I try to change the map in the Unit Placer, it does change to the right chapter. However, if I click off of the unit group, it will change back to the map where the chapter actually begins.
Here’s what I mean.

This is what happens after I try to change the unit group.

Before someone asks, I tried hitting write to rom after changing the map, but that doesn’t work. It only affects the changes to the unit.
How can I change the maps in the unit placer to make the cutscenes without causing the map to change back?

The map in unit placer doesn’t matter. If it’s really an issue, just note the coordinates by looking in map editor. Changing the map for cutscenes is done with LOMA or MNC commands in event editor.

The unit placer won’t “know” that units aren’t on the chapters main map until they are scripted to be on another map in event assembler. If you LOMA to another map spawn units after the LOMA and save the event (write rom) the units will show up on the intended map in the unit placer.

That being said, the Unit Placer is literally just placement data with no set map attached to it. The map in the unit placer is just a visual aid for setting placement data.