I do a lot of floppy imaging and some of my work on it has previously be discussed here[1]. I do not understand where they got the idea of "there are a number of disks that the Greaseweazle struggles to capture, namely the Apple formatted disks. If you have these disks in your collection, you may need to use an Applesauce controller."
The Applesauce is a macOS exclusive tool that has a contingent of dedicated users. While I have not imaged a wide sample set of Apple II and 800k Mac disks specifically, from my current experience the Greaseweazle is plenty capable of reading them. I would speculate the author was trying to use an included diskdef(a flux to binary decoding definition) for an incompatible disk. The Zone Bit Recording[2] Apple drives use is irrelevant when you increase the sample rate of the controller to accomplish the same thing. Similarly C64 disk drives are also ZBR but change the clock rate instead of media speed. So do not think that this means you need multiple drives and controllers when getting into floppy imaging, you can use standard PC drives with a Greaseweazle to read and write Apple II and Mac disks as well as almost anything else.
I have opened an issue on their github page for this site to seek clarification on this.
[1] https://news.ycombinator.com/item?id=39495973 [2] https://en.wikipedia.org/wiki/Zone_bit_recording
There's an issue on the FluxEngine git repo that may be related to this: https://github.com/davidgiven/fluxengine/issues/75
At the end of the thread, David Given reports that some PC floppy drives drop pulses when trying to read 800k Mac disks: https://github.com/davidgiven/fluxengine/issues/75#issuecomm...
So the Cambridge page might be saying "use an Applesauce controller" as a sort of shorthand for "use a drive from an actual Apple computer".
I received a response stating something similar on the git repo. It is still incorrect to blame the controller, and I suggested instead to provide some compatible drive models to use instead like they already do in the more generic sections of the article. It should even be possible to to use the Mac drives with the Greaseweazle with an adapter because the 800k drives from the Apple computers are just Sony drives with an optional eject motor installed.
Unlike the Apple II they do not have a custom Apple PCB. It's possible Apple requested some tweaks when ordering from Sony but I don't think they are all that special. So it should be entirely possible to read the disks with other drives. Based on the information in the page you linked stating any 720k drive is compatible, I suspect the higher read rate may be a vestigial feature that Sony over spec'ed during the introduction and standardization of the 3.5in disk.