you cannot save it. The name of this function clearly tell it's re-map for a game. Different game may have different combinations for extra buttons. So it's temporary remap.
I don't want to map random buttons for each game. I just want 2 permanent auto-fire buttons for the Button "I" & "II". The majority of the games in the PC engine and Turbo Grafx library are 2 button games and the original controller allowed for auto-fire(turbo fire) to be turned on/off during gameplay. This was part of the strategy to beating the games. Some examples are Vigilante, Dragon Spirit, Ninja Spirit, Moto Roader II (to get to the front of the race), Bonk's Adventure
eg. on an xbox360 controller.
I = A
I - Auto-fire = X
II = B
II - Auto-fire = Y
Is there any possibility of adding this feature for the PC engine core or to save the additional duplicate mapped buttons to a game configuration file?
It is a hassle to remap the buttons every time I play one of the above games. A keyboard must be connected to the mister in order to hit enter after the buttons have been mapped in order to accept the buttons changes.