Feedback on a folding fixie

 I built a dahon that was for scrap (obviously...) into  fixed gear, yes it is fun,  but the filing is crap.
 For a reliable compact folding bike, it has to have max 20"wheels or less,  if you ride small sizes on fixed you loose all the inertia of the wheel, that i find quite important.
 Also because the folding nature of the bike, the geometry of this bikes tends to be very upright and the rider weight very unbalanced, having all wight on the back wheel, wich i find also really uncomfortable for fixed.

so basically I guess it's possible to make something nice, but you need some time for design and development.
what I see here is a normal bike with hinges, that probably for this guys of 1' world war https://bsamuseum.wordpress.com/page-5/ it was an improvement, but i don't think it is now a days.