Nice job 3D printing going on there. What kind of filament did you use? Your assessment of Can Am's complacency of design. You could probably market these as an accessory, but 3D printing them could mean no profit. You would have to have a mold made, to bang out quantity, and that is big money, still, some people would consider buying one off pieces that would be unique. Those are the people you whack, especially if you color match them. I think you have a viable product.
If I ever went the 3 wheel route, it would be a leaning sidecar design I've been working on. I don't like anything that needs traction control, except some cars. There is now way to avoid that these days. The picture below shows the "Flexit side car", The sidecar and motorcycle lean together. This unit has been tested at 160 mph and it is rock solid. The sidecar wheel in in the same axis as the rear wheel, it is a very unique design. Numbers vary, but 700 to 900 were made, but they never come up for sale. I have already reversed engineered the rear tilting mechanism. It's been near impossible to find the pictures I have, but now I have them, though all the websites that had them are gone. It's just a matter of building it.
With so many damned surgeries, I can't get it started. I have all the metal stock built up. With my 3D printer, I'll be able to make a very finished looking sidecar. It won't look like the "Flexit" but I plan to use the frame design, and mirror my ZZR1200, it will look like two of the same bikes stuck together, but one missing the front wheel, and both leaning. The chain drive mechanism was very effective. It was very hard to find these pictures. I have reversed all of this stuff in Rhino6 and Rhino8. I am hoping to make this before I get too much older. The front of the bike is held up by a custom frame that holds the front bar of the sidecar, and allows for town in. It is not a universal joining, but a shaft on bearing left to right one plane set up. The rear of the unit attaches to the bike on a sub-frame, each is different depending on the bike, but not difficult to make. The chain connects the two allowing the bike and sidecar to lean in parallel with each other. Anyone who has the mechanical aptitude can see how this works. No traction control needed.
3D printing will allow, with general fiberglass work to make a very nice finished looking custom side car.