Relic Castle

So my game uses Pokemon-specific eggs and for the most part they seem to work fine... when the filename is just something like 058egg.png.

However, if the egg has a form applied to it, it seems to use the base egg even if the form is set to 1.

This is the base egg sprite, with the filename 058egg.png:



This is the sprite I want to use for when Growlithe's form is set to 1, and I've used both 058egg_1.png (the format that I got the egg files in, so I assumed it would work) and 058_1egg.png (which seemed the only other intuitive way to go about it):



With both filenames attempted, it always seems to default to this:


Hatching the egg shows that it's definitely set to form 1.


Any ideas why the form isn't translating to the egg?


Edit: I've been told that egg sprites don't differentiate between forms, so is there a way to make them do so?


Edit 2: Potentially solved in Discord.