@adayafterdeadline The latest BIOS for the MSI Z370 Gaming 5 (7B58v1A) has VBIOS 1063 VBT version 2.09, which is compatible with Skylake, Kabylake and Coffee Lake.
It also has GOP 9.0.1086 VBT version 221 which is also compatible with Skylake, Kabylake and Coffee Lake so no change should be required - good luck!