so that one app I am using inside the Task can use the python packages installed by the agent and I can control the packages using clearml easily

That's the missing part for me, You have all the requiremnts on the Task (that you can fully control), the agent is setting a brand new venv for each Task inside a container (the venv is cahced, and you can also make the agent just use the default python without installing anything). The part where I'm lost is why would you need the path to the temp venv the agent creates/uses ?