Restarting Joplin is a hassle and it makes customizing the css a painful process.
I'd like to see a plugin that can reapply userstyles.css to the markdown rendering. Perhaps the user could choose between using a hotkey or auto-detecting whenever the file has been modified.
And yes, I know about pressing F5 in the development tools, but that reloads everything. It's only barely less clunky and time-consuming than just restarting the app.