Windows Mobile 10 Technical Preview on Lumia 640 XL / I can't factory reset

[WPCentral Question]

So I would like to resume running Windows 10 Mobile Insider Builds on my Lumia 640 XL (US-AT&T) but continually run into a problem where the downloaded and installed Windows 10 Mobile build is corrupted and will not allow me to factory reset the device. Since the process of restoring to Windows 8.1 and then going to Windows 10 Mobile takes a considerable amount of time with my internet connection, I'd rather have a method that is 90% effective rather than how I'm currently making out. (Which is a failure rate of 100%)

I am using a strong WIFI connection when I do the update download. Should I disable reset protection before I proceed with the update? That is the only thing I can think of at the moment.