Using MTK IMEI V3.0 to restore a device's original, legal number after a software corruption is entirely legal in most jurisdictions. It falls under the category of device repair.
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: Works across various connection modes, including Meta Mode , Factory Mode , and Diag Mode , often without requiring the device to be rooted. Mtk Imei V3.0
Changes remain intact even after factory resets. Using MTK IMEI V3