While primarily a firmware flashing utility, SP Flash Tool features a dedicated "Readback" tab that allows users to manually extract and inject raw NVRAM partition images.
Readback function (for backing up NVRAM partitions); direct partition flashing; format options. mtk nvram editor tool top
Correcting WiFi MAC addresses and Bluetooth addresses if they become corrupted. Data Backup: While primarily a firmware flashing utility, SP Flash
If your MTK device displays any of the following symptoms, your NVRAM partition is likely corrupted or wiped: While primarily a firmware flashing utility