I would say the key is getting figuring out what sound profile you enjoy. Pass with Kef Reference 5 is brilliant match. The question becomes are you looking for something to add a hint of warmth, dead neutral or a bit of brightness.
Everyone says they want neutral, but in practice, few things are actually neutral. For instance, your Kef Speakers are generally considered forward/bright but you are pairing them with an amp that is generally considered warm. The net effect is likely neutral to somewhat forward/bright.
The Qutest and Node 2i are a wonderful test. Get those into your system and see if you like the system better. Chord's sound is a bit forward with a focus on clarity while remaining musical and dynamic. This can be a bit "in-your-face" in the wrong system or to a person with taste leaning toward laid back to neutral.
If Chord is appealing, then it is easy. You get a TT2 or wait for a deal on a Dave and then pick a steamer/server to match. Roon Nucleus or something of that sort. That really depends on your system, proximity to an ethernet cable, etc...
If Chord is not appealing and is too bright...then you need to look at warmer options and there is a lot of choice. There are literally too many products to list. The question is then, how warm? Could be dead neutral is fine. Could be you need something a it warm. It is very difficult to tell without you testing something in your system.
On a side note, PS Audio's Directstream DAC is an FPGA DAC rather than delta-sigma. There are wild differences in terms of quality and sound among delta sigma, R2R and FPGA DACs. I can show you brilliant and awful examples of each. We will do our best to steer you toward the brilliant options. The key is finding one you like the sound of, you like the looks of and integrates nicely in your system.
