Which component to upgrade 1st ?

The node is definitely the weak link. I replaced mine with a U-1 mini and it was a nice upgrade. Both were using an outboard DAC.

Instead of opting for the T-2, I suggest bringing in the U2-mini and a good NOS DAC of your choice.

For very little money, replace the power board in the bluesound with another from PD Creative and get an external power supply. For a few hundred dollars, it ups the game of the Bluesound by a lot.

@hilde45

Good suggestion on Node mods. I am curious if you have auditioned and compared any of the offerings from Lumin or Aurender with your modified Node.

Given the OP speakers, I would replace Chord Qutest with a good tube DAC before replacing the Node. I would try either MHDT Orchid or Border Patrol DAC.

A change of speakers will always have a greater positive effect than any electronics. Check out Devore!

You've got the foundation for a very nice system.  I'd be  inclined to experiment with some tube rolling so you can tailor the sound to your liking...both pre and amp tubes. If you do, be sure to give ample burn-in time before you draw any conclusions.

You didn't mention what phone cart you're using, but that's always a good place to research and experiment with to optimize what you already have.