@stephenw10 Yap, it did. Procedure was:
8GB USB flash drive, formatted FAT32
Stored my config as file "config.xml" on it
Checked on the PC that the config was fine and readable in Notepad++
Plugged it into my server (Dell R720)
USB Device passthrough to the pfsense VM
Booted pfsense from install ISO
Installer recognized the USB drive and also the config.xml, it wrote that config.xml was copied into the restore area before showing the "Reboot now" screen
Acknowledged the reboot
At startup it wrote that the config.xml is corrupt (0 Byte) and it died into the login screen
Pulled the USB stick, checked on the PC and found the config.xml file on the stick empty with 0 Bytes length
I did that several times, always with the same result and with the 2.7.0 and the 2.7.2 install ISO.