I also think most DACs in the under $2k level are not going to sound too different, unless you get a Schiit DAC.
I agree with this. These DAC chips are mass produced and their implementations in these units will be very standard / basic. The good news is the math & engineering behind these DAC chips has been developed for a very long time now and does its job VERY well. You want a different sound, you need a more exotic / bespoke design - which either can’t exist at this price point, or just slaps on a cheap tube buffer (cheesy), or is a plain bad implementation. At 2K (used) a Schiit Yggdrasil would do the trick if your system’s up to task. It’s fantastic. If you're going to ask "what about a Gungnir" (model below Yggy), I wouldn't. I've owned both and the Yggy creams the Gumby (Gungnir multibit).
Also, I’ve rolled many of each component type in my systems for a long time and in general DACs have less range & magnitude of different sound versus the other major components imo. From what you describe your result is not unexpected to me.

