Hello Vulgarbulgar, we have discussed this idea, but for the time being it looks like if that does happen, it won’t be for a while. You can however customize the calendar using our Themer’s Guide: https://theeventscalendar.com/themers-guide-to-the-events-calendar/
We also do have an Advanced widget that displays the calendar, and we have a tutorial on how to customize the widget: https://theeventscalendar.com/how-to-completely-customize-widgets/
We also use templates, and you can use your theme’s default template, our template, or a template you’ve created.
I hope this helps! If you have a specific thing you’re trying to accomplish maybe I can better answer your question, or help direct you at least.
Thanks!