Regarding the K135, I encountered a lot of problems with waves on the scan surface when the projector was set to full intensity. I don't know if this is a general problem with this model or specific to the one I have.
The waves were greatly reduced when I lowered the intensity.
This was with a Canon 60D using live view.
Panasonic GH4 4K with lens 12-35, Inogeni 4K to USB3 hdmi capture device, projectors: Acer K135/Acer K11/NEC V260X, Canon 60D, macro 60 mm, MagicLantern