There is not an issue with compiling and using ZFS on Linux, so I think it’s not accurate to characterize it as a no-go.
There is an issue with distributing binaries for ZFS and Linux together (note that distributing source is not a problem, it’s binaries, which is presumably what everyone is asking for.)
As of the 0.8.4 tag, the zfs-0.8-release is building against kernel 5.6 (and claims to have kernel 5.7 support, but I have not yet tested it), which means it is now a little bit easier to roll your own ZFS. This is WAY EASIER for non-root datasets, but it can be done on root with a little more elbow grease.
But if getting it working on non-root is too much work, you’ll not have a good time getting it working on root.
To build the ZFS kernel module:
git clone https://github.com/openzfs/zfs.git
git checkout zfs-0.8-release
If it builds without error, then you have a good chance of making it work for a non-root dataset on kernels 5.6 and 5.7.
As the Linux Kernel pulls away from ZFS, you can run into issues, so you definitely do not want to install the latest kernel until you’ve verified on the ZoL github that the new kernel version is supported.
Somewhat luckily, once you go ZFS on root, clr-boot-manager will no longer be able to install new kernels for you automatically (it does not understand where your root partition is anymore) In light of that, you don’t have to worry about things changing underneath you. However, you do now have to install your own kernels when you want to upgrade. Ensure you’re comfortable setting up systemd-boot if you want to go ZFS on root.
I’m working on some documentation to help, but I haven’t finished un-breaking everything yet.