For deleting the builds, at first I deleted the internal and external test groups thinking that was enough and this operation will cascade and expire all builds, but that didn't work.
Then I had to create a new group for the builds to appear, open each build, clear the Test Information section for that build, then expire the build. I had a lot of active builds so the process was tedious.
I think Apple can improve the experience here by adding a single button that clears and expires all the builds right inside the Transfer App criteria checklist.
Topic:
App Store Distribution & Marketing
SubTopic:
TestFlight
Tags: