I also ran a Bluesound N130 with upgraded power supply via coax into originally a Denafrips Venus 2 then into a Terminator plus. I never had issues with the sound. Both DACs are obviously a big improvement over the internal one. I also very much liked BlueOS and the upgraded power supply improved performance slightly but not night and day.
I did upgrade to the full Lumin U1 and the improvement in sound was not subtle. But for what the Bluesound is, it’s a great device as a first streamer. Ears don’t lie, and in my system, streamers make a difference. But of course it comes at a much higher cost which comes down to what it's worth to each person.
I had tone control off, subwoofer off, fixed output, MQA external on.