Wink Hub v1 NAND bitflips

Hi, I am trying to get OpenWrt booting on a Wink Hub v1, which has 128MiB of NAND flash. Without realising what I was doing, I used dd to write openwrt-19.07.1-mxs-uImage to /dev/mtd1. Unfortunately, this seems to have really screwed up the flash, as I am now getting uncorrectable bitflip errors when I read back from that device, using nanddump /dev/mtd1. I have tried using:
nandwrite -n -p /dev/mtd1 /tmp/openwrt-19.07.1-mxs-uImage
as well as
nandwrite -a -p /dev/mtd1 /tmp/openwrt-19.07.1-mxs-uImage
in the hope that one or other would recalculate the ECC bits, but to no avail. Can anyone suggest the best way to recover from this screwup?
I DO have a JTAG adapter that I can use to write u-boot back to the device, then restore the various partitions if I absolutely have to.

I'm hoping that there is a Linux-based way I can do it, though, if at all possible.