I've been sitting on my 90 size BUSA E-III for a year now, this winter looks like I'll take a crack at it. A couple of things I noticed running through the instructions.
-They rewrote their Taube instructions for the Fokker kit. The instructions call it a Taube way late in the book.

-They call for drawing a line on the fuselage side at the wheel block mounting hole, it would be a lot easier to draw these lines before you glue the two sides together.

-They call for drawing the centerlines on the firewall very late in the assembley, again it would be a lot easier to measure and draw these lines before you glue the firewall to anything.

Good luck on the build