Your missing the point of the endeavor. Building your own aircraft is a hobby and a learning experience (hence the 50% rule). Try new ideas, just be aware of the limitations. If you are not happy with the result, hang a gas engine on it. Its a good thing you weren't the Wright brothers neighbor.  

Oh trust me, I'm no stranger to trying new and unconventional things on my airplane  

But alas, you are right.  I will try to keep a more open mind.

Mark Beierle has converted one of his Thunder Gull ultralights to electric.

Here's a report from Apr 2020.    https://www.flyingmag.com/story/aircraft/technicalities-sing-airplane-electric/



Aeromarine’s Electrolite is Part 103 compliant:   https://www.avweb.com/aviation-news/electroair-electric-ultralight-to-offer-remote-piloting/

Wow.  That thing is actually pretty incredible.  I take back what I said.  You double the energy density of batteries and that thing gets right into the less efficient ultralight territory.  I was wrong.

Interesting info here:   https://www.aeromarine-lsa.com/electric/

https://youtu.be/CXYo2CfdPb4

Pros and Cons of electric power....   https://youtu.be/vpP23_zuOkM

Very interesting; thanks for posting the link.