It's more likely that BOOX doesn't allow their camera app to be launched externally. With version 3.8.12 (and 3.8.13 that was just released), the e-ink version of MobileSheets just tries to launch the OS camera app to take the picture. The BOOX camera app is not being listed as an option, so MobileSheets assumes there is no camera on the device.
I want to add that, at the moment, the e-ink version does not support the new camera functionality because I wasn't sure how many e-ink devices actually have a camera on them. Additionally, it will cause me to bump the minimum version to 5.0, which is probably fine as I don't think there are many e-ink devices below that. Once I add this, you may be able to take pictures with your e-ink device. I will send you a build that you can install to test this out.
Mike
I want to add that, at the moment, the e-ink version does not support the new camera functionality because I wasn't sure how many e-ink devices actually have a camera on them. Additionally, it will cause me to bump the minimum version to 5.0, which is probably fine as I don't think there are many e-ink devices below that. Once I add this, you may be able to take pictures with your e-ink device. I will send you a build that you can install to test this out.
Mike