Yes, can set them to fixed 100% in that menuIf you’re new to LMS and squeezeboxes it’s super important to first go to the LMS Settings/Players/Audio page for each squeezebox player (that’s your WiiM now) to set fixed volume. That’s how it works in the LMS universe.
I like leaving them on 100% setting in case I do have a particular case where the input is too high (fairly common with some loudness wars music) and I put the level down about 3 dB or so while still controlling volume from the analogue volume control
But that's just my peculiar way of doing things...LoL