Interrupt synchronization at the end of a file

[Judic]

For long synchronization tasks, which I can't necessarily finish without disconnecting the drives, I'd need an option to stop synchronization without stopping in the middle of copying a file (which can create a conflict and a loss of data that won't be recovered during the next synchronization, in some configurations). There should be a “Stop synchronization at the end of the current file” button!

[xCSxXenon]

That is already the current behavior. The stop button is more of a 'request' to stop. Any active transfers will finish first

[Zenju]

No, the "Stop" button interrupts file copying, unlike "Pause", which completes all pending file transfers first.

which can create a conflict and a loss of data that won't be recovered during the next synchronization, in some configurations

No this won't happen (unless you disable fail-safe file copy).