Small issue when using the built in update.
If updating AM while a miner is running, after the update and AM restarts, it does not see that there is already a miner running and starts a new instance of a miner.
I have also noticed this for the last two dev releases.
The problem seemed each time to be with remote agent (win) and t-rex.
Your observations are correct about T-Rex. When Remote Agent is starting it's looking at the running processes and figure out of a mining process is still running. For T-Rex this wasn't working correctly. I've implemented a correction for this that will be available in the next release.