This may or may not be in your interest, but anyway:
It would be interesting to have builds saved and then be presented a list of those builds (including QR codes and download buttons) for easy installation on test devices. Maybe the 10 latest or so, to not go overboard (might depend on account type).
I develop intermittently, but right now I’m working on 5 or so apps at the same time (and there will be more), and being able to install the same set of apps on multiple evaluation devices becomes an issue. I’m aware I could download the APK or IPA, but that adds steps. The best pattern to use for distinguishing apps would be the alias, as it’s unique, and needs to be unique in the stores as well.
AFAIK, only the APK and/or IPA files need to be kept in storage (and not the intermediate build files), and possible log file, so we are not talking huge amounts of data.
Other plans might have this, but the Plan page doesn’t list it as a feature.