How can I enable Single Pass Stereo with a custom format?

Hi, I'm trying to create an image for a lenticular auto-stereo display.

I have managed to do this with the standard RP and also with URP using two cameras and combining the output into a single interleaved image with a custom shader. However, I'd like to use Single Pass Rendering to speed things up.

Is this something I can do with the URP? Ultimately I need both cameras to render to the same image - with the R eye rendering only odd columns of pixels and the L eye rending only even (i.e vertically interleaved stripes).

Any suggestions?