Not to rain on yr parade or disparage the work you've done, but why? I can't think of any situation where both sides will be visible in the same render, so a simple adjustment of transparency should suffice between front & back based on viewing position.

With that out of the way, have you tried single sided planes facin' away from each other (or a box w/ separate MAT zones applied to opposite sides) w/ full or partial opacity assigned to the respective sides?

Luck on yr quest :)

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