I was thinking about a release without edit option. I do not trust on Windows Registry and a option in tools menu will be easy to found.
I'm sorry, but I would not do special release just for you. You may compile one if you want, source code if available.
Anyway, since version 3.2 you may disable editor (and opening remote files) by settings registry key HKEY_LOCAL_MACHINE\SOFTWARE\Martin Prikryl\WinSCP 2\DisableOpenEdit to dword:00000001. Since it is in HKEY_LOCAL_MACHINE, you may restrict users to modify it.