Good effort trying her out already!
I think she's tough to evaluate currently, she's a support master but without any "meaty" models to support currently. Further reveals will give a clearer picture. She definitely has some decent actions, her attack is just fine but her bonus works great with the crew.
As for her triggers to shut down schemes, as Mirage is friendly only, it will require a bit more guessing and timing, it only hits the first part of schemes like Vendetta, Secret Meetup and In Your Face so it can be easy to miss those windows. Probably a good thing though, it shouldn't be that easy to nullify schemes. Remake The Old World seems more generous in timing and being able to stop more in the way of reveals and end of game.
As for reasons to pick them in Explorer's, apart from your mentions, if there is a Bygone model who drops scrap (which I'd expect with Remnants Of The Aua being a bonus action on more than one revealed model), the Botanists could grow pretty fast with scrap being eaten for shielded. There is also an outside chance Jesse Halliday could find a home there, she can drop scrap, get in the way of people scoring by interacting, draw cards off scrap which is down, push enemy models, all things which seem to fit with Bygone. I'm not sure if they have enough of that already though.