Sorry if this turns out to be dumb and I'm currently using Ver 3.79g. I have set the Default Keyboard Mapping to BriefEx but the default editor keyboard shortcuts seem to remain. e.g. Search Forward is Ctrl-F not F5. I checked the editor mapping details for BriefEx and Search Forward is indeed F5.
Am I missing something basic? TIA.
Can't Change Keyboard Mapping
Search Forward is Ctrl-F not F5. I checked the editor mapping details for BriefEx and Search Forward is indeed F5.
I just checked the BriefEx mapping an can confirm this is almost correct

You are correct in that F5 is bound to SearchForward but Ctrl-F is bound to SearchWordCurrent.
Do you want to make the two key mappings equivalent

To do this just edit the keyboard mapping and in the shortcut edit field type in Ctrl-F and re-bind it to SearchForward function.
Cheers Jussi
PS: Sometimes half the battle is knowing the name of the keyboard function bound to a given key. What I do to determine this is record a macro, type in the key, stop recording the macro and then view the source code to determine the keyboard function name.