Thanks Suman - good to know. I was trained to always upload the config from the tomcat/7.5.3 days so I've always just done what I was told. I will add this as a voice from the field of someone who's been supporting this stuff since Grace Hopper did her cypherin' on an abacus - admin general download-config has saved me more than a couple times (I've seen disabling a trace in NSA corrupted our properties.xml - more than once).
Good to know that it doesn't appear to be necessary - but I think I'll keep doing it because it's a prudent backup mechanism.
Thanks for testing and educating!