A crucial aspect of the user's query is the reference to "OTA remove." OTA (Over-The-Air) updates are designed to patch security vulnerabilities and improve system stability. However, for a device running modified firmware to bypass MDM, OTA updates pose a significant threat. If the device successfully downloads and installs an official update from Oppo, it will likely restore the original security framework, re-locking the device under MDM or, worse, "bricking" the device due to software incompatibility.

Before attempting to remove MDM and OTA firmware, make sure to backup your data to prevent any potential losses.

OTA firmware, on the other hand, refers to the process of updating a device's firmware over-the-air, without the need for a physical connection to a computer. While OTA updates are convenient and ensure that devices stay up-to-date with the latest security patches and features, they can sometimes cause issues, such as bricking the device or introducing unwanted changes.