I actually publish everything as original on Medium first — before even posting on my site.
I know this has some disadvantages in terms of SEO and perhaps others. I don't focus on SEO at all and I still drive a lot of traffic to my site (which helps with my other revenue streams).
I would keep it 100% original on Medium first; especially if you're looking to maximize your revenue generation with the Medium Program/algorithm.
I hope this feedback helps!