I'm sure this would be an obscene amount of work...however...
I'm sure I'm not alone in getting progressively fed up with Apple's pursuit of shiny and thin verses power. Cheetah runs great on my £2.5k MacBook and £2.5 imac but I bet the 2nd hand windows laptop with a Nvidia 1060 I picked up for £650 would slay them both! (ironically the same price as an equivalent eGPU)
Returning to windows is becoming a serious consideration for both cost and power and Cheetah is the only piece of software solidly keeping me on my Mac at the moment!
There is nothing comparable on Windows with Cheetah - everything is either fully featured and a fortune or budget and 10% of Cheetah's feature set. None of them have as good workflow and none of them start up as fast!
I'm not leaving MacOS just yet, but the next time I upgrade my hardware I'm likely to be very temped with windows.
I don't claim to know Martin's private thoughts or dreams etc. for Cheetah, but if I was a betting man I would say there is no chance that Martin will produce a Windows version of Cheetah. He has already starting making the necessary changes to incorporate Metal for the upcoming versions of Mac OS, which is a big task. On top of this, he is also working on new features and the like. I'd say his hands are pretty full as it is.
Macs are becoming more and more a joke. It used to be easy to justify paying the price for a Mac, but not anymore. The hardware seems to be at least a year old and the prices are more and more ridiculous, the machines less and less user upgradable, I don't want much, just to be able to swap memory and it would be nice to be able to add new internal hard disks... hell I would settle for eSATA (Thunderbolt again is overpriced).
I remember the ads for the new(current) iMacs style gushing over how thin they are when viewed from the the side. That right there was the moment they lost it. I sit in front of my computer not off to the side gazing lovely at how thin it looks. I was happy with the previous "fat" design, the current one not looking much different form the front. A bit of thought and their much vaunted user experience genius and they could have realised ports on the back are not helpful or accessible, and with the thickness of the previous style they could have added slide in bays for hard drives.
I think the only thing that keeps me a Mac user is I prefer MacOS to windows, and Linux just seems to much effort. The only two apps I have that are Mac only are Cheeth and Xcode. Xcode is mostly awful and like much of the Apple eco systems misses out on stability and useful if uncool features in favour of flashiness, which is a shame because MacOS has some really nice features. As for developing iOS apps for me at least it is painful (mostly because of Xcode which I wouldn't describe as a professional IDE), and I am only on my first one!!!
I would be sad to leave Cheetah behind but I am not sure how much longer I can justify paying over the odds for outdated hardware. (Though I expect to own this iMac for a number of years yet)