I know this was technically previously submitted, but I found that the glow layers on wings will only render on the right-wing if the regular texture file has something "covering" the glow. It doesn't matter if the glow file has something set on the top or bottom. If the regular texture file has the wings blank, the glow will appear correctly. This can be reproduced on any dragon type, it's not specific to any certain breed.

There's also an issue where entities will render through glow layers. This includes signs, dropped items, item frames, and clouds.

This is my first GitHub issue posted, sorry if there are mistakes.

Decided to give this a go and yea, it does indeed work if the base texture for the wings are blank (for 1.18.2, but may work for 1.18.1)
That explains the translucency i observed in my initial report of the bug cuz the ice and ghost dragons don't have textures under the glow, though with how my crystal dragon's wings look i might stick with something more opaque in case the rendering can't be fixed (i think i've seen glow layers bug out like this before)
I had a screenshot but both github and my internet threw a hissy fit over me uploading it (github was claiming the file format wasn't supported.... its a png file)... so if a screenshot magically appears in a few days then that means my internet stopped being a brat

I do believe this is due to the special way the second limbs are rendered on the dragons. (which is just taking the limbs, inverting their position matrixes, and then rendering again)

It's pretty hacky... and unfortunately that was the original authors method. I do have a fix in mind and it will be done the proper way.

Thank you for your patience.