[Bug] Lighting propagation through opaque full and half blocks

[PaleAsphodel]

Describe the bug
Hi! My current project relies very heavily on copycat blocks, especially slabs, bytes, layers and panels - they allow me to make one block thick walls that have different textures on each side. That's very important because each of the rooms look very different from the hallways (see screenshot)
Before, I had to use two-block thick walls: this resulted in awkward deep "doorways" where I had to put the door in the middle, or even worse use 2 consecutive doors - which really doesn't sell the mansion aesthetic.
The problem is that light goes right through the copycat blocks, even when textured.

Expected behavior
It would be nice if copycat blocks, as soon as they are textured with an opaque block like wood, would block light in a way that makes sense- for example a copycat slab, or 4 bytes assembled to a slab, or 8 bytes assembled to a block, or a panel blocking a hole.
On the other side, blocks that are clearly not meant to block light because they can't fill a full block or full half-block, like copycat slices or steps, should stay the way they are.

Screenshots

Desktop (please complete the following information):

• Minecraft Version: 1.20.1
• Mod Loader Forge
• Mod Version copycats-2.1.1+mc.1.20.1-forge

Additional context
It'd be amazing to have a solution for this - the project relies on an extensive lighting system that allows you to turn the lights on and off in the different rooms and hallways independently of each other, so having the light just pass right through the walls won't work. On the other hand, using copycat blocks is an amazing way to make one block thick walls with different decor on each side and by extension nice and realistic looking doorways.
Thank you!

[Bennyboy1695]

We are aware of the light propagating through blocks it shouldn't do currently. We do plan on fixing it and leaving the ghost block with the light being able to go through it.

[Azagwen]

This happens as well when you make a roof of Copycat blocks, completely ruining any house's lighting by soaking it in daylight.
I would consider this pretty critical even if it's just a cosmetic inconvenience, as it quite drastically defeats the cosmetic purpose of the blocks by making some build's lighting uglier

EDIT: for copycat slope layers, a weird fix seems to just be to update the slope shape using another layer, which will remove the light bleed; this also applies to copycat bits, and likely most "Stackable" and "Multi-State" blocks

EDIT 2: Here I built a structure with copycats without fixing lighting by hand block by block, and the result I end up with is the terrain below is entirely illuminated, despite being blocked from the sky