I'm also a little confused about where Explore Stars comes into play here. I use the Asiair extensively (almost exclusively) via serial. I polar align first using the Exos polar scope. Then I turn everything on and use the Asiair to polar align accurately (I usually try to get in under 30" total error). From that point, targets can be centered using plate solving in the Asiair.
I'm not sure how the 3-star alignment would work. Meridian flip is a function of the Asiair and can be turned on or off in the Asiair app. If it's on, it shows at the bottom of the Autorun screen the time until the flip.
Hope this helps.
Scope: ES ED102
Mounts: ES EXOS2-PMC-8, SkyWatcher Star Adventurer
Cameras: ASI1600MM Pro, Nikon D7500
Lens: Nikon 200-500mm, Tamron 70-200mm G2, Nikon 120mm manual lens
Misc: ZWO ASI120Mini Guide Camera, ZWO 30mm mini guidescope, Stellarmate, Asiair
Software: Kstars, SkySafari, ExploreStars (android), Pixinsight, DeepSkyStacker, Regim, Astrostakkert, LR/PS, RNC-color-stretch
Computer: Macbook Pro, Surface Pro 4, iPhone, Fire 7