Updated my streamer so do I now have to burn it in. Denafrips dac required it,

If you've got new electronic parts, the sound is very likely to change subtly over time. 

I built my own amps from Nelson Pass designs and was able to compare two boards with identical designs, but with higher-quality parts in the new board.  At first I was so disappointed with the new build because I spent so much money, time, and effort on the parts and it actually sounded worse than the original.  Two weeks later it was leaps and bounds better, as I had originally hoped when I undertook the build.  After that experience I'll never doubt the reality of burn-in again. Or parts quality for that matter.   

And you don’t need your amp turned on to break in DAC and Streamer…

I felt my Streamer and DAC improved after a few hundred hours use, but regardless, they will break in or not as you use them, so just enjoy and come to your own conclusions in a month or so...it's a petty debate as everything breaks in regardless...

Doing something like this gives a feeling of satisfaction. A sonic improvement is highly unlikely. 

Yep …. No surprise here.

My brand new MOON 280D MiND2 streamer/DAC manual highlights 400hrs as the recommended break-in period, during which audio performance will improve.

Now being about a quarter way through it to date…. Yup …. There is a distinct progressive audio improvement to date, and experienced in steps. It has not been a linear experience, but rather in a ad hoc series of steps.

I leave it on full time at least for now, even when I’m not playing tunes through it.

It may get a wee bit better after 100 hours but I don't know that it would be a big difference. The best person to ask would be tech support of the manufacturer.

no