Intellectual property/patent related stuff won't ever be in a changelog by any company and whatever product. This is the main reason changelogs are so.. lacking. If (I can't stress "if" enough) any change is made into the changelog policy then it can only include non-IP stuff. Everyone should understand this.
Version 1002 2018/07/06 8.76 MBytes
PRIME Z370-A BIOS 1002
1.Improve system performance.
2.Supports Intel next gen processor.
Version 1406 2018/09/19 10.12 MBytes
PRIME Z370-A BIOS 1406
1. Improve system performance