Optical switch PCBs have been available for JLFs for years.
No one ever continues to manufacture them though, which must mean something.
I have modified Toodles Spark CEs in my joysticks.
It only took $150 worth of mods to make the JLFs feel the way I wanted.
(and I still wouldn't mind a slightly smaller throw)
FYI using optical switches might limit your choice of actuators.
I don't remember what size actuators are currently in mine, but I do remember reaching a point in testing where the actuator was too big to work. These switches work by breaking a beam between an IR emitter and receiver. The biggest actuators get in the way before the joystick is even moved. Actuators made of white plastic also threw them off.
I don't like that the sensitivity isn't adjustable on these, but I guess the regular microswitches aren't adjustable either.