Attenuate Output from NDS..?

I don’t have an NDS, but you can do the same thing on an NDX2 so you might have it available.
For me, this is found in System Settings / Volume Mode. If you set it to variable you can limit the output. It may affect SQ as others have mentioned.

You could also try enabling system automation and using the volume control on your phone/tablet (or in app). That’s what I do, and while the volume knob on my 252 does stay in the 7-9 range (10 if I’m feeling naughty), the volume can be increased/decreased in small increments in the app or using my phone volume buttons.

There’s no variable volume option on the 1st gen streamers, so not an option in this case.