Transfer between 2 FTP do not take care of the thread limit

When transferring files from a FTP to another, SmartFTP do not limit threads.
I setted a thread limit to "5" in the Transfer Queue panel, but i was banned from the FTP because i exceeded the connection limit:
[20:34:00] 6>421 Too many connections (8) from this IP

The remote browser may also uses some connections. Reduce the number of workers in the transfer queue.