All the other controls on the MISC page are no simple linear controls like Fog/Fan, so it's a bit tricy.
you could consider:
fixture "Fazer"
{
custom
{
label "Fog"
msb 0 0,255
}
custom
{
label "Fan"
msb 1 0,255
}
}
Then both function are on the CUSTOM page. But now the GLOBAL FOG button won't trigger this unit any more.