Wheelchair Axle Diameter

I have my original ZRa with stock wheels. I also have a set of Sun Fusion wheels I bought a few years ago. I don't recall being asked about my preferred axle diameter, but the new Sun wheels came with compatible 0.5 inch axles. Then just two months ago I bought a Permobil Helium manual standing chair. My expectation was that the wheels on it, Spinergy SPOX, would be interchangeable with the ZRa wheels. Unfortunately, the Spinergy wheels on the Helium chair have 12mm axles. Since the chair was made in France, it is not too surprising, in hindsight, that the axles are a metric size. It did surprise me, though, since I've never been asked about my preferred axle diameter during this or any prior order. So now I might be stuck with wheels that work fine on the chair they're with, but nothing else. The workaround seems to be to replace the Spinergy hubs with a 0.5 inch compatible version and find a machine shop to ream out the camber tube to 0.5 inch, a job complicated by the two degree camber. If I only wanted one-way interchange, I could probably make the 12mm axles fit the 0.5 inch hole in the ZRa camber tube by use of some 0.010 inch shim stock. But I really want them to go both ways.

Any suggestions or how others have dealt with this?

Wheelchair Axle Diameter