As a developer, It’s currently too annoying to see highlights having a limit of 31 parts rendered with highlights maximum. This is very annoying for most games, for example if a game wants to add highlight to players, but it allows more than 31 players, some players wont have the highlight, Image of max rendered highlights:
A workaround? Insert a model and put all of the parts you need inside it, then insert a highlight inside the model.
While this hacky way works, There is a bug(or atleast, intended for models) with it. look:
Put highlight at every part u want:
And put highlight at model: