Making a bounding box with more depth than width

Hey there! I've been making this mob for a Minecraft mod that's longer than it is wider, and it seems that the width and depth cannot be changed individually... is there any workaround for this?

also, I'm running MCreator 2022.3 and working with Nerdy's Geckolib Plugin, so if there's any issues/features pretraining to what I'm using I just wanted to mention it