Not sure about pickup use, not the conventional ones at least simply because they were developed around a N-S bar or two, in different shapes and configurations but at least Magneplanar speakers use a distributed "the diaphragm is the voice coil" system to allow thin light large diaphragms to move air, similar to electrostatic speakers, and it requires magnetic field "strips" on the whole surface ... and we know a speaker is a microphone in reverse, at least conceptually.
"Many on the same surface" magnets are used in stepper motors, actuators, position sensors, etc.; "created using a regular Magnetizer and custom designed yokes, I guess this company has some complex multi coil yoke, each coil concentrating on a small area of the magnet, (which is a **huge** achievement in such small sizes as offered) , and such magnetizer coil configuration is computer controlled, hence nthe Software mentioned.
Yes, I bet they can achieve a particular magnet configuration or another, at will, without needing to machine a new yoke every time.
Cool idea , I watched the videos and what they promise is feasible.
Thanks for posting
PS: these are some ways magnets can be magnetized, we are familiar with the first two: axially magnetized (Alnico cylindrical rods) or through thickness, as in alnico or ceramic "rectangular" bars, but many more are possible.
Notice that at least two create lots of tiny magnets on a single surface.
FWIW humble "fridge magnet sheets" are also magnetized in narrow strips for better fridge cabinet adhesion.