This sounds a lot like magnetic bubble memory that intel, fujitsu, IMB and TI made in the 1980s.
That too had multiple states per "bubble". However the higher-order bubbles were generally not used. The reason was, it was hard enough keeping the single bit (zeroth order mode) bubbles stable at high circulation and high density.
Since here the domains are fixed and the disk moves it might be easier to use higher order magnetic domain modes.
Magnetic vortices are significantly smaller than the bubbles in bubble memory. Because of this, there are no "higher order" states - you have 4 distinct magnetization states (CW/CCW, in/out), and there are no in-between states. The trick is figuring out how to get the switching speed down using exchange bias coupling and crazy anisotropy effects.
My mouse didn't work. Why? Because they included an update to the Bluez stack, to support a change to the kernel, but the KDE4 Bluetooth support hadn't been updated to support that new Bluez stack. Their solution? Drop bluetooth support in Kubuntu Intrepid. WTF?
Sometimes projects have to make tough decisions in order to meet deadlines or to otherwise keep development going in the right direction. They probably weren't happy with this either, but don't think that you could have done any better if you were in their shoes.
You knew the job was dangerous when you took it, Fred. -- Superchicken