Looking for best streamer without DAC under $3500

Well its a fair price and you may find they would go down some given the current economic crisis.
I use Spotify on my phone only to play in the car as Qobuz beats it soundly in SQ at least in my system to my ears.
That said the Spotify catalog is larger than Qobuz so there is that for sure.

Has anyone compared the Lumin U1 Mini against the Auralic Aries G1?

OP
If you really want to try the D2, take a look at this
at the asking price it is just $1575 USD.

https://www.usaudiomart.com/details/649607429-lumin-d2-silver-trade-in/

I’d get a used Innuos Zen Mklll, which I’d think should provide some sonic upside. But if not, just turn around and sell it for little/no loss so very little risk involved and use those funds to buy a Pavane Level 3, which will certainly yield improvements.  That’s what I’d do. Best of luck.

Bricasti M5.  It sounds as good to me as my recently sold Aurender N10.  Small, Roon Ready, and great sounding after break in.