The usage nature of this API is commonly polled by Portal. With ETAG it would gain better performance E2E.
I wonder if the perf improvement would be that meaningful given that the amount of data sent back is typically quite small.
The 5 sec polling from Portal might justify this. Portal pulls 20 items at a time (so it depends what small means). The nature of it is also that it does not change most of a time. As by product, we might think about using this to suppress getdeployment spamming traces.
The etag could be done cheaply by say every time one starts deploy/redeploy, we update the time on active deployment file (currently only update when successful). Just a thought.