My config for A500 WHDOpener

kickstart_rom_file=PROGDIR:Roms/Kickstart-34.4.rom
#kickstart_key_file=PROGDIR:Roms/rom.key

filesys_nofsdb=true

# cpu settings

# chipset settings

fast_copper=true

# memory settings

# gfx settings

gfx_depth=8

show_leds=true

# sound settings (sound_output="normal" or "none")
# (sound_channels="stereo or "mono" or "mixed")
# (sound_bits="8" or "16")

sound_output=exact
sound_bits=8
sound_channels=stereo
sound_frequency=22050

# joy <n> where n is lowlevel unit in amigaos target. In SDL target it's be the enumeration order.
joyport0=mouse
joyport1=joy1

# overlay display
amiga.use_overlay=true

# screen type (public, custom or ask)
amiga.screen_type=custom

So not much changed comparing to default settings. Works great on my Powerbook.