Make MFi controller pretend to be a ps3 controller?

Hi, I have two Nimbus controllers from Steelseries that I use on my iMac. I have been using them to play LEGO Star Wars: The Force Awakens on Steam, and have come across numerous problems. The main problem is that it recognises the Nimbus as a controller, and so sets the input for player 1 and 2 to the controllers, however it actually doesn't support the Nimbus, and so all of the controls just say "No Input".

To play the game I have a program off GitHub called GamePad Menu which allows me to map the controls to the keyboard. The problem is, that I will be playing and it will just randomly switch back to the gamepad itself as being the input source, and i will have to go back into settings to change it back to using the keyboard as the source of controls (which i have mapped on my controller).

What I was wondering, is if there was any way to make the Nimbus (or other MFi Controller) 'pretend' to be a PlayStation controller so that the game recognises it natively? Maybe there is a driver or something that allows me to map the A, B, X and Y of the Nimbus to the X, O, square and triangle of the PS3/4 controller to make the game recognise it as a controller and not have to muck around with input sources? Or maybe the program that I am using (GamePad Menu) could be configured to send out a signal that games can receive?

If anyone can help me in any way I would be extremely grateful,

Cheers