That's how it is when bitstreaming DSD unfortunately. A lot of DACs require volume (both internal volume and system volume) to be set to 100% otherwise you either won't hear anything or will hear noise.
I would highly recommend putting in an analog volume control/attenuator (AKA potentiometer) somewhere in the chain, yes. There's choices out there with one that comes off the top of my head being the Schiit Sys. It'll probably depend on if you're using unbalanced or balanced for the audio output. Looking on Amazon, Sweetwater, B&H, etc. you'll find some at different price points that support different outputs with differing quality.