Is your feature request related to a problem? Please describe.
It appears that some mods such as Create: Copycats+ are able to mimic the look of other blocks through NBT data. Being able to dynamically set specific blocks to be given properties such as emissives and reflections based on the block that it is mimicking means we would be able to fully support these types of mods. Tinker's Construct's (Hephaestus) tools use NBT in this way as well.

Describe the solution you'd like
Something such as block.10320 = modName1:blockName1:nbt.X=Y would definitely work, but considering the reason mod devs probably use NBT like this because of the sheer amount of combinations there are, we could do with a more dynamic type of system....perhaps we could have an entry such as for example copycats:copycat_slope:nbt.BlockEntityTag.Item.id=[DYNAMIC] to indicate that this block needs to mimic the properties of the mimicked block ID.

Describe alternatives you've considered
I'm not exactly sure if there is alternatives? I mean besides speaking with the mod devs about a potential solution? One might be able to have a "state" where all it does is say what ID it's mimicking, which would let us be able to do copycats:copycat_slope:id=diamond_ore, but with the sheer amount of blocks within the game, let alone mods would quickly make the file into a total and utter nightmare to navigate through.

Additional context
Add any other context or screenshots about the feature request here.

Ideally the block on the left would be emissive and glowing, and the one on the right should not. As of right now this is impossible to do.