Do Stickers work with the Indoor API?
No, Stickers are not meant for Indoor Location, only regular Beacons are.
In theory, I guess even stickers should work for indoor positioning. Given if you know the X,Y position of the sticker you should be able to calculate the users position using triangulation. Maybe that is not supported in the SDK for indoor positioning, but I guess thats due to a strategic choice. Or am I misread?
I'm afraid Stickers are not meant for Indoor Location mostly due to their range. Regular Beacons range up to 70m, while Stickers only up to 50m.
Also Indoor Location settings can make much more significant impact on Sticker's battery, than on Beacon's, because Beacon's battery is way bigger and lasts longer.