Hi there,
I just flashed my Gigabyte Brix GB-BXi7H-5500, Intel Broadwell U Premium, under Linux (debian sid), using flashrom v0.9.9-r1954 on Linux 4.15.0-1-amd64.
Worked like a charm, I just needed to boot using iomem=relaxed.
The chip is marked as "untested", hope this success report will help.
Big thanx for the great job, please keep-on doing it !