[U-Boot] NAND BBI swap on iMX53

Hi all, I've noticed that mxc_nand driver doesn't implement BBI swap for reading factory marked bad blocks on NAND devices, as suggested by Freescale:

https://community.freescale.com/servlet/JiveServlet/download/329191-260869/A...

BBI swap is implemented in Freescale iMX53 BSP (which use an old u-boot version 2009.08) but not DENX official U-Boot. Isn't this a dangerous behaviour? As far as as I can see it can lead to an irreparable loss of factory bad blocks markers. Can someone please give me some information about this topic. Thanks

Best regards Luca Ellero