Thanks for bringing that up, I think it is important, if not critical! Reading your post, I realize that I never read the one you linked.
As a TAC member, let me try to give some insights in what is going on at the TAC level, at least from my perspective. The second sentence of this reply gives some hints: Days are only 24hrs long!
Many of us, e.g. @jzp, @KevinJW, @alexfry, @SeanCooper, @nick, @carolalynn, @matthias.scharfenber and all those I forget, are participating in many, too many of the ACES and ASWF VWG, then add to that other initiatives, e.g. ETC, and finally work!
To the point of discussions behind the curtain: I don’t think there is any particular agenda besides making something useful for the industry and community. I certainly discuss with many of the aforementioned people in other channels, e.g. Slack (in public or private channels), email, etc… but I have never seen anything but people trying really hard to make ACES work. I think it is fair to say that we all are very much motivated about ACES, even when receiving counter-productive punches on Twitter & co.!
The TAC has a private space on ACEScentral where topics can be discussed. TAC members are asked to review the various documents there, e.g. CLF Specification, but it is too my sadness very much unused. Here is one of my reply to @Annie that you might find interesting, (one of the ~3 posts of 2021):
Related, I tried to get Daniele invited as a TAC member but never got a reply unfortunately:
Please keep in mind that I’m not trying to find excuses, I want to give some context.
“Leadership requires belief in the mission and unyielding perseverance to achieve victory.” – Jocko Willink.9 sept. 2021
Edit: I would like to emphasis that this is just my personal opinion and certainly not the views of the TAC. This is my personal diagnostic and I might be wrong.