Apple has not officially announced the number of self-signed iPAs installed on iOS devices. To avoid locking the device, it is recommended that you follow the following rules when installing the self-signed IPA:

1. Try to avoid frequently installing self-signed IPA on the same device. If you need to install multiple applications, you can consider using a third-party application management tool for management.

2. Pay attention to the selection of reliable self-signed certificates and signing tools to ensure the correctness and security of the signing process.

3. When installing the self-signed IPA, you need to trust the corresponding certificates and applications on the device and follow the relevant operating procedures and safety specifications.