Hi, gang. A few times already, I spoke on this list of my need to see the weights of subtrees on header lines. Nicolas Goaziou was kind enough to write the function for computing the weights, I wrapped some Lisp code around this, and shared the result on this list. In that code, I had a command which computes and displays the weights, and as soon as I modify the buffer, the weights were disappearing.
I recently had the need to frequently re-evaluate the weights after modifications, and got tired of repeating the displaying command after each modification. So I modified the code so the weights get updated instead of disappearing. Bastien also suggested that I turn my code into a small library. If you are curious, see the results as: https://github.com/pinard/org-weights It works relatively OK for me. Bugs surely remain. :-) François