Describe your suggestion...
the NBT rule in random_entities.properties has multiple variations (raw: | regex: | etc.) and one of those is range: which checks for an integer value in a list. The problem is, many useful NBT values are of the "float" type, which cannot be checked by "range:".

Usage example: with Random Mob Sizes "ScaleFactor" NBT value (which is a float), textures could be applied based on entity size.

Does another mod also do this?
No.

Does OptiFine do this?
No.

regex could do this but it is of course more costly.

I will look into adding support for this but it would most definetly be disabled by default for compatibility

This wont be a high priority, seeing as its possible via regex and different behaviour to OptiFine.

Not to be overzealous, but thank you.