I only add the path under each "Special" note as to where to find the CSS file. Everyday notes don't need this, as they use the normal userstyle.css then.
First line is for my private PC at home, second line is for my work laptop.
The downside of this: If I change some CSS on my work laptop, I have to make the same change on my private PC, because I use my daily Bujo for work stuff, too.
But with a git repo that's not bothering me very much.
<style>
@import url(C:/Users/private/.config/joplin-desktop/userstyle-bujo.css);
@import url(C:/Users/work/.config/joplin-desktop/userstyle-bujo.css);
</style>