Howdy @mmccarthy404 ! We unfortunately do not have such a feature available presently.
However, I am happy to pass this along to the engineering team for consideration!
Further, it may be worth taking a look at the connectapi package, which has a function for setting environment variables. As a result, you could always write your own script for setting environment variables easily.
It's worth noting that changing environment variables does restart the app, so it would affect users currently using the app. This is much less hacky than the supervisor script, though, because it is not truly global in the sense that it affects all pieces of content simultaneously. 
Definitely not a perfect solution, but could be used with CI / RStudio Add-Ins / other workflow optimizers to make your life easier, perhaps 