Sorry Ed, but I'm spurred to take exception with a few of your points here.

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An air cooled transverse vertical twin is a horrible design. First off, it's much wider than it needs to be.


Nope, it's not. It's actually a very good design, and in effect is reasonably narrow. The only problem with the design can be the vibration inherent in a 360 degree crank placement, but as is evident with the modern Hinckley Twins, that can be almost completely eliminated with the addition of a balance shaft.

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The longer radius that all that metal has to traverse has an adverse effect on handling.


Please explain what you meant here. Were you talking about "piston speed" or "flywheel effect" or something else perhaps? In any regard here, I must say I think your supposition is overstated.

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Second, the bore size is limited by how far apart the rider can comfortably spread his knees.


On a "vertical" engine, yes, that is somewhat true....however....
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This is the reason Norton had to cant the cylinders forward to get enough bore to make 850 CC's.


...this was not the case with the Norton Commando. The Commando's engine was slanted forward in order to lower the profile of the new "Isolastic" frame and thus lower the center of gravity of the motorcycle. The Commando's engine(which btw was originally a 750cc displacement and was only increased to 850cc the efforts to keep it competitive with its growing Japanese displacement competition) was no wider than the "vertical" twin Norton 650cc Atlas which preceded the Commando, and thus it was not slanted forward because of any need for "space" on the last iterations of the Commando series with their 850cc displacement.

Yep! Just like a good Single Malt Scotch, you might call me "an acquired taste" TOO.(among the many OTHER things you may care to call me, of course)