Hi! I reported an issue with org-babel-tangle performance issues with lots of noweb references here:
https://lists.gnu.org/archive/html/emacs-orgmode/2022-01/msg00484.html
Using 2b49d6fd9c04020a8132bfcfffa449e3e05b47e1 on my personal (but not yet public) config that demonstrated that issue I see a great improvement!
It has 124 source blocks, 70 of which are noweb-ref, and I believe some of those noweb-refs also refer to eachother if that matters for performance considerations.
org 9.5.2: 1.28, 1.33, 1.32
org 9.6-dev: 0.46, 0.44, 0.43
Nearly 3x or 200% faster!
Thanks to Ihor Radchenko and others who worked on this!