I was happy to read this and directly tried it but it seems not to work.

My external diff tool still gets the link-files as input parameter and not the real files. I re-started smartGit after changing the option.

Anything else I have to consider?

This could happen ;-) - but maybe this feature could be enabled within this low-level options But I would already be happy to be able to select several files and lock them.

the idea was not really to lock a folder but to right click to a folder and to lock all the files which are in this folder respectively in the folder tree