Came across this error message when I was attempting to run your script on my google pixelbook.
Uh oh. Erase/write failed. Checking if anything has changed. Reading current flash chip contents... 000000-0xffffff:R Reading 16777216 bytes starting at 0x000000. ignoring error when reading 0x0-0xffffff done. Good, writing to the flash chip apparently didn't do anything. This means we have to add special support for your board, programmer or flash chip. Please report this on IRC at chat.freenode.net (channel #flashrom) or mail flashrom@flashrom.org, thanks!
This is the set that the program said it didn't recognize. Intel Kaby Lake Y w/ iHDCP2.2 Prem