but they are nowhere near as convincing as the retroarch crt shaders.
I would probably still be running advmame for everything if it weren’t for those shaders in RetroArch. This and better analog support is the reason lr-mame2003 became my default, but it was mostly for the shaders. Now, Advmame is primarily for vector on my cab until someone adds hi-res rendering to the vector video in 2003.
To my knowledge you can't, but I haven't put a lots of time into experimenting either. Acceleration, for example, seems to only affect the max speed. If you continue to test and find out something different, I'd be very interested.
in order to set the digital inputs as analogue (in addition to keeping them as analogue too).
It appears that the current fba core accepts only analogue (thumb)stick inputs for arcade machines that used analogue hardware such as wheels, joysticks, pedals, etc, something that wasn't a case previously and still isn't on MAME.
For anyone having the same problem (and doesn't use analogue sticks) this seems to be the only solution currently but I'm not sure if this will interfere with anything else.