Bravia engine after bootloader unlock!

So as the title reveals, I have unlocked the BL and tried a few custom roms. Didnt liked any so back to stock. But i just came to know that we loose bravia engine after we unlock the BL. But as I m on stock 4.1.2 I do see the bravia engine on/off toggle. Its quite confusing. Have i really lost bravia engine? Or it just gets restored when we flash stock roms?
Well If i have lost my BE, any way to restore it back? i mean will locking the BL do?

thanks!