I just wonder what is it that makes the difference in strength between a 22" genuine and a 22" non-original ???

Are they made in completely different ways or out of completely different materials? You wouldn't think there can be that much of a difference surely ? V8 or else ...

Quality of the raw materials. The cheaper ones will be cast with a mix of alloys that has more impurities and not heat treated in the same way.

i got mine with a set of fakey 22's, liked them, but soon, both fronts goth slow punctures, and just moved the wheels on.
i just could not find any decent looking place, that would weld and garuantee the repair. other places, said everyone gets similar with these cars. -heavy car, with sports car wheels. the sidewalls, just cant absorb the bumps. so a tyre fittter/wheel supplier told me. it like driving with runflat tyres, -that are flat!
i got some 20 inch wheels, and the drive, was much better. i now have 20's with oversize tyres, and still like the look. (standard tyres on 20' to me look a litttle lost in the wheelarches. and RRS tyres on either 20, or 22 wheel, are even worse.)
have you considered getting a fitted set of 20 inch wheels/tyres, and running them for a while, to consider switching?