They could go all kinds of ways. I defintely don't want the standard put certain costume on for a little bit scenario. Or for things to go into a full on justice system like ESO.
I would like the WoL and a few scions to go into the empire with a alter persona sort of similar to the griffin. Where the empire thinks you are someone they know of, but no one can actually verify you are the true one except for certain empire characters.
The idea would be something like Aether currents. But the unlocking is not gained by finding green glowies in obscure places. Let's call these Notoriety quests. FFXII played with this some but it was a simple running around town shouting stuff. Below is the simple way in that game.
Here the premise is to influence certain people or groups of people to grow a fondness or respect for the WoL. When first entering any soldier occupied area the WoL must first don that persona, trying to keep his/her distance from the empire while exploring until all possible persons are influenced enough to a point the WoL can relax more, even walk up to most imperials and talk.The player party rescues the character of Captain Basch from a dungeon, some years after his supposed execution. Basch needs to spread the word that his death was faked and he was alive. How? Let Vaan cause a commotion. Vaan’s idea of a commotion? Running around a city yelling that he is Captain Basch.
It would consist of doing, saying, acting whatever is needed to sway people in key areas. Some scenarios like gaining entry into a prison, sewer, etc would have story and key npcs hidden throughout. During the course if you fail or get too close to the wrong people, make a bad choice, or whatever. You get a Bounty cooldown, soldiers aggro. You can take down one if it's in a secluded area. But if you run into 3 or more you get automatically jailed.
As for the open world outside these hot zones, there could probably be the standard aggro. I hope unlimited sprint gets added and rather than heavy, sprint is disabled for a brief time. Perhaps the empire soldiers do not reset or deagro as soon as your standard enemies from previous expansions.
If SE still wants something Aether current like they could have climbing or deep diving currents where you gotta have them to traverse a deep dungeon/cavern or sewer system. Flying currents are cool but we already had those two expansions.