I just released 1.0.0 of the Transducers library for #commonlisp 

I've made quite a few improvements: https://git.sr.ht/~fosskers/cl-transducers/tree/master/item/CHANGELOG.md#100-2023-09-07

Highlights:

Operating over (and into!) plists and hash tables is now possible
CSV support
The introduction of a few custom Conditions

Next step is to complete the Emacs Lisp port.