Well, I was just about to admit my opinion is factually incorrect - but then I figured I would ask: would these two projects have been better recieved if they had been designed for 2-rail only with "Overland" levels of detail? Could you make it 450 total two rail, and if 3-rail folks wanted them, charge more for a conversion kit? Isn't that what the OP was asking for?
I believe this is exactly the answer the OP was seeking. For me, had that E-7 been die cast, I probably would have had to have one.