Well I feel like a right wally. I applied your code above and it works! However, I must have been mistaken as Yoshi runs awfully with gles2n64 as the emu. I imagine this is why the author blacklisted it. Most of the screen is black, and when you can see elements you only get bits here and there.
God only knows what I was thinking. Apologies to Mitu for taking up your valuable time with this. :-(
Basically i had started out using arcade controls using the Picade Hat wired to arcade controls'
That is recognized by retropie as being a keyboard, later on i set up a FC30 Pro for use with the console systems.
The issue i had was while learning how everything worked i had used different methods on how i was changing settings then i would change something in the a zip.cfg file or the per system retroarch.cfg then get really wonder why it wasn't changing when it was set in one of the overrides that i forgot i had used.
as i say, this time round i am trying to stick to rules as to what i use each type of config for so i know where to look to fix things later.