Yeah, the problem is they need to be cracked. If it came from America it would surely have gotten cracked and one of the many images online would work in NTSC I'm sure. Sometimes you have issues there because the cracking groups might put in a PAL intro which messes up an NTSC game, but inevitably someone didn't break the game.
But if it came from a PAL territory originally, was copy protected and cracked, well why waste your time with a separate NTSC version when you've already cracked the original? That being said, American's, be they pirates or strong willed individuals who wanted to punch anyone who dared attempt to strip their backup copy rights given to them by law, they had copy programs which would copy the disk.
Kyrofluxed images, I don't care what you've been told, can be copied to actual floppies. Be that actual kyro or from this Supercard thing. I might have to make a video on this because it's starting to anger me how many people assume they can't without having ever attempted it, obviously. When someone says it can't be done, I assume they're full of it, and I'm usually right.
A simple install to WinUAE, and a well placed .dll file will make WinUAE support Kyro images, multiple ones, including the ones I received. From there, with a good copy program, you can turn those fluxed images into .adfs, which I have done, and are fully usable inside of WinUAE at least. As Intric8 said, they are massive at 2mb, but they work in the emulator. That's just the copy protection. Beyond that, if a fluxed image is not copy protected, it couldn't be more simple to put that to an actual floppy disk, which I have done.
It has nothing to do with them being fluxed, find a copy program that will copy those disks in real life from the actual floppies to another floppy, and I guarantee you I can use that program to copy the fluxed images to a real floppy. The problem is... what program can do that? X-Copy has not worked for me.