I recently developed a utility that allows you to write to extrom - however it must be inserted into rom because WM isn't playing nicely with loading other drivers. I have provided an easy to install OEM package, just drop the OEM package to install the hide/unhide tool, and replace the OEM_FLASHDRV.dll module in OEMDRIVERS with the one provided.
You can find the tool
here.
I am now accepting donations as I spend a considerable amount of time working with this device. If you enjoy my work, donations are appreciated.