FFS Manual must target Linux users also,...

[hapEcat]

FFS Manual must target Linux users also, and not just Windows. There are enough differences between Windows and Linux OS's, to warrant a dedicated ".pdf" manual for Linux users, or at least include those differences in the current manual. FFS is the best "data BAK", cross-platform solution for Linux that I have found, but sadly is geared one-sidedly towards Windows.
Only SyncBack rivals FFS in its cross-platform capabilities, is a slightly more "user-friendly" platform, but not as fast as FFS. I've used SyncBack for many years, but slowly making the transition to FFS over the last couple of years, and just recently becoming a "Donation Edition" user.
I, dual-boot W10/Linux Mint, but predominantly use Linux, so cross-platform BAKs of a common DATA partition, between 2 vastly different OS's, is essential.

[Zenju]

Let's not forget macOS. Best solution is to have single manual with as little duplication as possible. That said, is there something specific in the current manual that should be expanded for Linux?

[hapEcat]

Perhaps Linux/Mac sub-sections detailing the subtle differences.
That would still comply with the 1 manual philosophy.
There are many new Linux/Mac converts that struggle with the learning curve a new OS presents... But most of the "old" Linux crowd don't have this problem, just the new folks.

[Zenju]

I wouldn't want the manual to become needlessly verbose while adding little benefit. Most chapters should be OS-agnostic already (screenshots aside). And when there are relevant differences, the manual distinguishes, e.g. https://freefilesync.org/manual.php?topic=schedule-batch-jobs

[xCSxXenon]

What differences? Syntax differences are the only thing I really encounter, which anyone that can successfully use Linux probably knows already.