Adding X/Chromium to the AstroBox image

I have a Pi3 and an Adafruit PiTFT 3.5 screen attached via GPIO. I’ve installed the latest AstroBox image, and followed the Adafruit guides to get the screen enabled so it shows the console on boot however I cannot get it to boot directly into X or run Chromium.

Using Raspi-Config I can either boot to the GUI and have to manually log in (which I don’t want) or boot to the console already logged in (again, not what I want).

Does anyone have a list of steps that work with the AstroBox image specifically to get X installed and auto booting into Chromium with a page displayed (kiosk mode)??

Thanks!