I'm working on a PR.
The current version of build-installer.py doesn't use LTO/PGO because installers are build on macOS 10.9 where the compiler doesn't reliably support this. Recent compilers should work a lot better.
The upcoming PR enables --enable-optimizations when building on macOS 10.15 or later (Xcode 11 or 12), mostly because that's what I'm testing with.
I'm listing 41100 as a dependency because having that is the only way to make use of this PR at the moment: build-installer.py uses --enable-universalsdk and 41100 introduces "universal2" as a set of architectures that can be build using Xcode 12. All other sets of architectures require Xcode 10 or older.