I got something working with :
Soundcard: hw (Direct hardware device without conversion) <here this is my SMSL AD18 but should be the same for other USB DAC or AMP)
Param ALSA: default 80:4::
Command line options: -a 40:4:24_3:1 -b 50000:50000 -p 90 -r 96000 -u hMX
And tada, 96KHz is now displayed. But I do not manage to make to work higher than 24/96, which is already great !