Apologies for exhuming such an old thread but the question was one I was curious about as well (even way out here in 2023). This ensuing curiosity led me down a rabbit hole of articles, blogs, boards, and videos which brought me to one maybe-possible-could-be answer, which is: "Which variant would a manufacturer make available?" Aside from the obvious canopy shapes, there's also engine variants of inline vs. radial (BMW VI 7.3D vs. the Bramo 323A-1 Fafnir respectively... among others) and then the nose shapes make for a dynamic range of silhouettes and dimensional variants... Unsurprisingly, a company could stick to offering model kits of the Do.17 exclusively —and no other types of vehicles at all— and still never get through all the variants.
Sadly, if any of the larger manufacturers did launch a kit, I'm sure they would receive a litany of hate mail for offering the one variant that Grumpy McGrumble hates: and being how prolific McGrumble can be with posting his discontent, it's no wonder none of them will touch this plane.
Anyway, just my 2₵ but I thought to chime in since this plane is still really cool and a 1/32 scale offering (in any of its schizophrenic identities) wouldn't net any complaints from me.