Yeah, Manjaro is nice. To bad there still are quirks with hardware as yours and you can’t, at the moment, fully enjoy it.
Is part of the sof-image and indeed /usr/lib/firmware/intel/sof-tplg-v2.0/sof-adl-max98390-rt5682.tplg
file is there, not quite sure what we are missing. Unless is about some kernel boot parameter, or something else. I guess you saw this on the forum
Worth mentioning them so nobody does later, hopefully someone will jump in with new information.