It IS possible to convert the canvas to a 3D object for BPR render using Francesco Mai’s Pixol-to-3D plugin. However, the challenge is that the pixol canvas is only really meant to be viewed from one angle, so that if you tried to get 2 decent angles for each side of the binocular effect you might begin to see the worst parts of the fact that many features on the work in question would have no ‘sides’, just ‘fronts’! My guess is that some pixol canvases could be modified and reworked to get it done, but that anything that really played with a lot of depth would be near impossible, or just plain too difficult to justify the effort.
Having said that — you are probably familiar with HR Giger’s experiments in this area where he painted a stereogram series BY HAND…if an artist of that magnitude took the challenge, they could prepare two separate pixol canvases and simply get it to be perfect by eye!!! Maybe that person is you!!!