Thank you for adding the Select a Standard Language modifier. Can you please add the Choose a Character Size modifier?

Use "Options". That's the point of Options - to create options for the user to select.

I want to be able to format it the same thing as official species are formatted.

Then this is a feature request, not a bug, so should be in Feedback forum.

Although, I wouldn't hold my breath about this being added any time soon. You can already achieve the effect with very little fuss and very easily, so adding another way to do it isn't going to have much of a priority.

If you copy the official human, the size trait has a modifier for choosing a size, but its not available otherwise, so I thought it was a bug.