Can this not be implemented quicker without that, as it's essentially the equivalent of 2 explorer remote panels side by side?
Indeed. But that's not gonna work. People will expect the transfer to work and would complain all the time :)
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Can this not be implemented quicker without that, as it's essentially the equivalent of 2 explorer remote panels side by side?
See also Can I transfer files between two remote servers with WinSCP?
If the local panel is waste of space for you, you can use the Explorer interface: