my take, my understanding (second hand from reading/thinking, not from my own ears as i have never had a node w lps upgrade) is that the power supply mod addresses only one aspect of the node’s (necessary) cost engineering, which is the cheap and noisy internal smps
the node also has a fairly inexpensive analog driver stage, rudimentary digital noise management, timing clock and dac chip - these are not addressed by the polish lps mod
the zen stream is a different animal - there is no dac inside, it just streams, built for that express purpose, it has a better clock, better noise management in several aspects (ifi is expert at this, galvanic isolation, active noise cancellation and so on) ... i would think within its specified purpose the zen (also powered by a similar grade lps) should still handily outperform the node with lps as streamer