I just found out that sandbox agencies cannot release or transfer sub-accounts.

This should be allowed. Even though release/transfer is a small process, it's an important one and being able to test it inside a sandbox agency would be a meaningful enhancement to what sandbox agencies can do. The whole point of a sandbox is to safely practice and validate real workflows before running them on a live agency, so leaving this out creates a gap in that parity.

Request: Enable the release/transfer sub-account function for sandbox agencies, matching the behavior in production.