I think you’re asking how to setup a mof so it effectively contains a variable (in this case $env:temp) and thus pulls the correct value dynamically on the target machine and doesn’t actually pass the $env:temp on your authoring machine.
So I’ve only found two ways t do this personally:
I ensure the module that will be generating these logs defaults to $env:temp so I don’t have to define it in my configuration. Sometimes it means a slight tweak, but that’s the joy of the modules being so accessible.
I use the script resource to do said work. This way I can use setscript and it can contain whatever environment variables I want … it all runs on the client anyway.
I’m not aware of how to deliver a mof that contains variables outside of setscript. I’ve been proven wrong before, however, so I’m interested to see how others might handle this.