The so-called full-time self-study exam is just that the social self-study exam aid institution (training school) arranges you to go there for classes. The exam is still the same as other people who don't attend classes there.
You can sign up for this social assistance institution as long as you pay the fee.
The short-term self-study exam is more expensive, and it is not recommended to participate without special circumstances. In order to avoid being cheated to varying degrees.
The right to issue self-taught diplomas belongs to the local provincial self-taught departments, which has little or no relationship with aided schools.