Alpha Map Fails with Multiple Alpha-Mapped Cutouts

[AdrRen]

Alpha Map Fails with Multiple Alpha-Mapped Cutouts

To Reproduce
Create multiple planes with alpha-mapped cutout textures.
Attempt to bake them as a combined texture through "Alpha Preview."
Notice that the Alpha Map does not appear as expected.

Expected behavior
I expected the Alpha Map to be properly seen/baked, combining the cutout shapes from multiple objects into a single texture.

Possible Workaround
To make baking possible, I connect a black-and-white Alpha Map to the Normal Map input of my Shader and enable "Mix Textures" in the properties of the "Normal Preview". This doesn’t produce a proper Alpha Map due to the normal map’s default (128,128,255) background color, but it at least gives me something I can refine in Photoshop afterwards.

Screenshots