I run ExpanDrive (www.expandrive.com). We use a derivative of macFUSE (https://osxfuse.github.io/) on macOS.
Third party kernel extensions on macOS are on the way out.
On M1 machines any third party kernel extension requires a reboot into recovery mode, lowering the security settings, and then finishing the install.
This is a terrible and unfriendly model for users (by design). This is the primary reason these Google/Box/etc aren’t shipping M1 versions of their software.
But that’s okay, they’ve got something better they’re working on. Just keeping it a little quiet right now since it’s not 100% done.
The replacement for apps like Google & Box Drive (and everyone else) is their new File Provider framework (https://developer.apple.com/documentation/fileprovider), which they quietly launched but didn’t publicize at all. It’s basically a technology that enables something like Dropbox Smart Sync (project infinite) built directly into macOS fully managed by APFS.
It’s a pretty big departure from the macFUSE style interfaces we've been using for years now. File Provider apps are userspace extensions that work with with placeholder files and on-demand hydration of remote files by the system via APFS. It’s a pretty cool framework, but pretty new (and a little raw).
Box/Google/Dropbox/Microsoft will all eventually be using it, but the rollout has been slow.
The whole macOS File Provider project is an off-shoot of the iCloud drive and iOS file provider projects, but with one key component they’ve added called the replicated extension that has an apple-blessed extension to APFS called “FPFS” (presumably file provider FS) that can intercept read/writes/etc to these on-disk placeholder files and download content (and thumbnails!) on demand. Provides data directly to spotlight indexes, etc.
Whereas FUSE is a really low level API exported into a safer user-space process, this is a little higher level. You give the file provider framework lists of directories, help it monitor changes, provide item info and then it will in turn issue callbacks into your extension to initiate downloads to a temporary location.
Benefits
1. All on demand, driven by placeholders. “regular” sync downloads contents ahead of time, this is not the case with file providers. It’s more like network filesystems in this regard
2. Doesn’t eat up free space. Providers can mark their content as “evictable” which lets APFS know it can toss out the data if space gets low. But what I think is extra interesting is that when you mark the content as evictable it doesn’t even register as being used against free space. You could bring down a 10GB file from the cloud and your free space remains the same
3. Integrated with all the higher level APIs so that applications that open a file with swift/objective C don’t beachball while waiting for a download (for an open) to complete. They appropriate waits and expectations are in there now
4. All sorts of other stuff, happy to keep going