It would be interesting to see if you can compare a new streamer with your Bluesound 2i. I have the 2i and also a newer streamer (a DIY built to very high standards), but in all my comparisons, the DAC is the component that made a noticeable difference. I honestly don’t see that a very large upgrade in sound can come from a streamer-only change compared with other weak points in the system. But if you think the rest of your system is as strong as it can be (including room acoustics), I suppose a streamer upgrade is the next logical step.
P.S. Perhaps the greatest improvement I have made in my system by a factor of 10x was to put my speakers on podiums. Not subtle.