“[M]any players only log in once per PTU phase to briefly inspect the latest features or new ships before waiting for the live release. This led to very high player loads in the first hours of each wave release, combined with comparatively high server costs and download provisioning, but not the sustained playtesting we would have preferred. As a consequence, towards the end of a PTU phase, we sometimes lacked the necessary numbers of testers to put the servers under pressure once the most significant bugs had been fixed.”
Content retrieved from: https://massivelyop.com/2023/08/11/star-citizen-will-now-invite-players-into-its-ptu-based-on-their-activity-in-an-effort-to-stress-test-builds/.