Tom.......Im very curious as to what engines were used in the example at Traverse City.If you could get the pilots name or phone/email that would be helpful too,as you are practically next door neighbors to me..
I had a conversation with Nick Sr. last week regarding the twin Beech design.Of interest are his opinions on :
Engines: He feels G38s are naturals for this design,citing reliability and simplicity .He is not a fan of electronic ignitions.I cant buy his arguments entirely but what the heck,its his design!

CG: He is not aware of any particular inherent need for massive lead nose ballast to balance.He says keep the tail building light and watch the weight of the finish.

Wing washout: He says enough is designed in on the original plans.

Finish: He says go with lightweight glass cloth and epoxy under paint ,wings included.