[mcarni]

the terrible problem that I am facing is that if the rom is a zip file I have to drop the controller and grab the remote, press "context button" and select the emulator
this makes me lose my concentration and usually end up defeated by my son ;-)

 If I understand you right, you don't have any button on your controller mapped to a context menu in "Kodi enviroment" ( for me it is X button on my XBOX controller). What controller do you use? If there is any button you don't use frequently in Kodi enviroment you are probably safe to map it to context menu (X button on virtual Kodi controller as far as I remember). It shouln't influence the in-game controls in any way. You are going to alter totally different mapping.  

 thanks gnaag,
yes i see I could achieve that with remapping the context menu on the controller
but i think it would be even better if it was possible to set a specific default action to all the files within a specific path.
so when you press the context menu for the first time on a zip file under let's say mame/roms path the usual window pops up to ask you which emulator to use
there could be an extra flag at the bottom that says: " set this emulator as default for all zip file in this path"
so when I decide to change game and move to the next rom (still in the same folder) i will not have to go through the context menu again because kodi will know that all zip file in that path need to be open with mame2003 for instance.

Hope I made myself clear, i can try to do some copy/paste of pictures to show what i mean (not now unfortunately...)

M