Hello bcoyle,
I don't know if you could get double fisheyes with the Insta360 One X? If yes, then you can try to split them in "normal" fisheyes and process these in standard version.
There is also the possibility to sort two fisheyes (from one shot) as a camera group and then set group type to station, to tell Megashape/Photoscan that both shots are made from same position.
But generally the resolution and sensors of these 360 cameras are very limited. I only use them in very tight spaces, where I can't use normal cameras. You can also have a look in support section, where you will find some papers.
Hope it helps
Kiesel