In previous guides, we'd explained how to fix Null IMEI on Mediatek and Wi-Fi NVRAM 0x10 errors on a Mediatek Android phone. Some people have complained of IMEI disappearing or NVRAM 0x10 reappearing after a factory reset.
The good news is that you can permanently write these to your MTK Android phone using SN Write tool / SN Writer. Simply get the MD1_DB and AP_DB files from the firmware for your phone model and follow the SN Writer tutorial