And because we all tear our hair at those who whine on forums and never follow on if their issue was fixed or not, after a successful coreboot update using your flashing script, this issue is now solved!
$ cat fixed.txt
$ sudo qubes-hcl-report work
Qubes release 3.2 (R3.2)
Brand: Purism
Model: Librem 15 v3
BIOS: 4.7-Purism-2
Xen: 4.6.6
Kernel: 4.9.56-21
RAM: 16298 Mb
CPU:
Intel® Core™ i7-6500U CPU @ 2.50GHz
Chipset:
Intel Corporation Skylake Host Bridge/DRAM Registers [8086:1904] (rev 08)
VGA:
Intel Corporation HD Graphics 520 [8086:1916] (rev 07) (prog-if 00 [VGA controller])
Intel Corporation Device [8086:9d24] (rev 21)
Net:
Qualcomm Atheros AR9462 Wireless Network Adapter (rev 01)
SCSI:
Samsung SSD 850 Rev: 2B6Q
Samsung SSD 850 Rev: 1B6Q
HVM: Active
I/O MMU: Active
HAP/SLAT: Yes
TPM: Device not found
Remapping: yes
YOU ROCK! THANKS!