Sorting Groups for Opaque Objects?

Looking to replicate the 2.5D style found in Paper Mario/Cult of the Lamb (flat drawn sprites in a 3D modelled world). I’m considering making the sprite characters proper opaque objects, but it seems that Unity’s Sorting Group component only works on transparent materials.

Is there a way to make Opaque object sorting groups? Otherwise I’d likely have to just offset the components of the sprites along the Z axis, which could lead to odd sorting when they’re close.

It is technically possible to force a specific sorting order for opaque geometry.

However, it won’t change how they render, because the whole point of opaque objects is that their sorting order doesn’t have any visual impact on the final pixels. This is explicitly the intended design for how opaque meshes are handled by GPUs. The only way to actually impact the “sorting order” of opaque meshes, at least in terms of how the final rendered image appears, is by adjusting their depth from the camera.