[1.0.51] Traders/Invaders are using the wrong outer gate - How to change?

[TacticalMaster]

There was this trader that was on their way to visit my outpost. However, I noticed on the map that they're just standing there, right outside my wall, and not moving. So I had no choice but to talk and trade directly with them while they're still stuck. However, they were still standing there nonetheless. But then I realize, that when I opened my gate, they started moving again. And instead of stopping near the outer gate, they stopped at my inner gates instead.

This is related to my "complicated base bug" that I've finally gotten out (and still waiting for a response from developers). Well, highly likely, because it's by far the most complicated base, despite essential defensive wall builds, that's causing the game's algorithm to not work correctly.

On the other hand, is there a way to re-designate a gate as the "Main Outer Base" gate --- as a temporary workaround?