Yamaha had to draw a line somewhere in the sand where things on one side were global and things on the other side were set within each Performance. There is a hybrid - which isn't used frequently - where there's a global setting that can be inherited or set uniquely within the Performance. I'm not sure there's much of that this generation. At the PART level - there is this choice to "inherit" settings from a higher place in the hierarchy - like Part Clock Unit (Part Unit Multiply) - where you can set a local value or inherit by setting to "Common". But this strategy wasn't used much at the Performance level for leveraging a system global vs. assigning a unique value to allow for either strategy to apply.
Instead, Yamaha elected to make the system more flexible (program uniquely within each Performance) vs. making the system easier to batch program (use of globals - or hybrid). This generation the general paradigm shift was away from inheritance (voice -> performance structure) and towards flexibility (flat performance-only). I think this is more of a philosophical direction change than necessarily a capabilities/feasibility change. To go against this is somewhat fighting city hall - so not sure what's global and what's not is going to change much.
Eventually - it probably ends up taking less time creating your own Performances that work within the system than it does trying to find a way around the system. This is usually what ends up happening over here. Bump into a wall - then work within those boundaries.