If you know Javascript you could very easily write a plugin in Obsidian to do this. Just have the plugin replace any markdown with the Unicode equivalent on save.
Great question though, it’s actually making me wonder why this isn’t a thing in normal plain text editors!
It was for me. Been using Windows for 20 years, installed Aurora after all the MS craziness this year and haven’t looked back.
In my case it’s turned out to be a whole lot better - my laptop runs cooler, battery last about twice as long, and I no longer have any issues with going to sleep when I close the lid.