from task pick-up to "git clone" is now ~30s, much better.

This is "spent" calling apt update && update install && pip install clearml-agent
if you have those preinstalled it should be quick

though as far as I understand, the recommendation is still to not run workers-in-docker like this:

if you do not want it to install anything and just use existing venv (leaving the venv as is) and if something is missing then so be it, then yes sure that the way to go