Is it possible to read F2FS-formatted SSDs in macOS? The title says it. I have an external drive for use on a Linux system, and would like to read it on macOS (High Sierra).
The drive is encrypted (I have the password).
Is possible?
Natively?  Definitely not.  F2FS was developed by Samsung for use on Linux.  I don't know of any mainstream Linux distros that support this out of the box either.  From the cursory research I've done, it can be added to the kernel to support it at compile time.
To get this support on macOS, you'll need to add support using Fuse much like you add support for any of the 3rd party file systems.  Currently, it's not listed as supported by Fuse.
What you might want to try is to load up a VM running Linux with F2FS support enabled then create a USB Device Filter to immediately mount it on the VM and not mount it on the macOS host.  VirtualBox supports this.