There's an open bevy issue for this at https://github.com/bevyengine/bevy/issues/4372, seems like the most straight-forward path would be to go in and resolve this in the engine. Barring that, there are a few more patch-style fixes we could try:
Manually creating a far simpler interim shader for sprites, possibly at the cost of PBR
Analytically modifying mesh shape to fit the contours of a non-transparent sprite
This might have some side-benefits in collision, mouse picking, etc.
There's an open bevy issue for this at https://github.com/bevyengine/bevy/issues/4372, seems like the most straight-forward path would be to go in and resolve this in the engine. Barring that, there are a few more patch-style fixes we could try:
Will look into this more later.