So you brought up an interesting point, that TMP folder for messages can be used as a place holder for token replacement, DTK jobs, modify configurations, etc.
Need a place to put temp files right before copying them down to the client.
Part 2 is what you discovered in the check box and I guess its a personal preference and perhaps does have a best practice of only enable logging when you need to.
I dont listen to that ... far too many years of DS experience so I have that enabled for the clients to upload their logs and I have the axengine log set to level 3 with a 20 MB set. If there is an issue I then crank it to 5 but afterwards the info gets to be useless.
32 GB of log files seems excessive even for this stuff .... Turn it off, restart the services, and see if that is any better.