As an update I'll say that since I posted this I have burned two and a half tanks of E30.
This is around 475 miles.
I haven't noticed any performance issues. The bike runs fine; it pulls hard and sounds great!
My average fuel economy city and mixed highway (55/65/90 mph) is right about where it has
always been. I am averaging 48 or so.
I'll update again when I destroy something. Until then the experiment continues...