> The apps become invalid after about 7 days after compiling them. So for development its fine but if you are building utilities for yourself to use, it could be an issue.

Exactly, they deliberately crippled the feature to make it too painful to bypass their corporate bureaucracy. It's only useful for the narrow uses that suit Apple. In no way is that ability comparable to side-loading on Android.

To be clear, even if you do pay up, then they still expire on each anniversary of you signing up.