RelWithDebInfo default MSVC flags are pessimising

Have discovered a performance regression with Windows builds after switching to RelWithDebInfo (to enable crash reporting)

RelWithDebInfo uses /Ob1 whereas Release uses /Ob2 : and for modern C++ code, this is a large pesimisation.

Value comes from Windows-MSVC.cmake:

What’s the recommended way to reset / override this in my project, while keeping everything else as compatible to future changes as possible?