Update: I found a similar post here: In 5.5, RunUAT.sh always triggers a full rebuild on macOS, even for brand new default C++ projects that suggested setting PCHUsage = PCHUsageMode.NoPCHs in your Build.cs. This led to a small speadup, but I’m still at about 8 seconds.
@mikeroberts3000, apologies for pinging you in here, but I am wondering if you ever found a way to speed up build times on macOS for C++ builds in development?