Instead of overwriting the latest version being used, it should automatically go to the Add Versions tab. Re-download with a significant time delay is not practical, even if it was not a stable version. Note: in my opinion (I have download limits).
I have gone ahead and entered a request for the feature you are suggesting. I would like to add that we do have GitHub/Source available to our users which allows you to build released versions of the engine, including specific versions like 4.7.3 for example.
Follow along with this documentation to get your account set up for source to be able to build different versions of the engine.
Thank you for taking the time to submit this feature request, and we ask that if you have further questions or need assistance please let us know!