I'm thinking of renaming the "Monster: Animal: Horse" category on the custom creature palette to "Mounts" and pushing it up to a major category which would house templates for ALL mountable creatures...
What do folks think of this?
I use brackets for this method.
Parentheses put things at the top of the list, but as to not have the top cluttered with all manner of categories I use brackets to place them at the bottom. Thus, all my (Dynamic) and dynamic (Mounted) selections all appear first, then the wealth of creatures, then at the bottom I have things like [Mount], [Object], [Unique] for NPC models and those intended as one-off appearances, [VFX], etc.
Go with what's comfortable for you, it's easily changed on this end, but I, like you, prefer them organized.
Edit: I completely misread that, as I missed palette and was thinking appearances. Haven't tested it within the palette so don't mind me. Too much going on today. My apologies.