@shift I don't have dedicated threads for each individual lr-mess system I run, but the short answer is "more-or-less all of them".
Just to rattle off some of the ones I've tried on my Pi, with decent-to-perfect performance:
Epoch Super Cassette Vision
Various plug-and-play systems (both "official" and bootlegs)
Fujitsu FM Towns
Once you get down how the core works (which admittedly is a bit of a nightmare), it's insanely versatile since it runs all the same systems as modern standalone MAME (according to the current docs, that's roughly 32,000; that link at the top is a good few years out of date). Arguably the most powerful core in all of RetroPie.
Many thanks for your advice @BuZz. I modified the startup script as you mentioned and it still works.
My understanding is that BasiliskII should ever load the 'keycodes' file so the host keyboard layout (the one configured in Raspbian/RetroPie, here) is taken into account, whatever international layout it is. Without the 'keycodes' file, only US-layout would be recognized and typing from another host keyboard layout (i.e French AZERTY, German QWERTZ...) under Basilisk would produce weird result. If I understand well, the keycodes file contains the USB keycode for any environment BasiliskII has been built for (so, the Linux framebuffer, here).
By the way, loading or not this keycodes files every time BasiliskII starts is not necessarily the most important point. With your permission, I would rather suggest that there is something to fix somewhere, since BasiliskII doesn't open this file when it is told to do so from its basiliskii.cfg config file.
Nuance barely worked properly on Windows back in 2007. Unless someone's been working on making it work a lot better and on ARM, I don't see that happening. You'd have a better chance of hoping MAME handles it soon.
Executing: /opt/retropie/emulators/dosbox-sdl2/bin/dosbox -conf "/home/pi/RetroPie/roms/p2000t/Monkey.conf"
fluidsynth: warning: Requested a period size of 64, got 480 instead
fluidsynth: warning: Failed to set thread to high priority
fluidsynth: warning: Failed to pin the sample data to RAM; swapping is possible.
DOSBox version SVN
Copyright 2002-2019 DOSBox Team, published under GNU GPL.
CONFIG: Loading primary settings from config file /home/pi/RetroPie/roms/p2000t/Monkey.conf
SDL: Current window pixel format: SDL_PIXELFORMAT_ARGB8888
MIDI:fluidsynth: loaded soundfont: /usr/share/sounds/sf2/FluidR3_GM.sf2
MIDI: Opened device:fluidsynth
One joystick reported, initializing with 4axis
Using joystick Xbox 360 Wireless Receiver with 6 axes, 15 buttons and 1 hat(s)
Using driver "opengl" for renderer
I am happy to investigate more if it helps the community. If we collectively believe this is a problem with a 20-year old emulator, I am also content to call this one good enough and run without a joystick. :)
So... Crop overscan does nothing when I set it in video settings.
However, there IS actually a first/last scanline in the emulator options, which allows you to essentially move the problem off screen. This seems a very "dirty" way to deal with it though (as I'm having to crop off some of the bottom few of the 240 lines).
This doesn't look like a typical RetroPie installation - what version of RetroPie do you have installed ?
You may have ran out of disc space on the sdcard, you can check that by exiting EmulationStation and looking at the welcome message.