PHP Global Options - What does it cover?

I noticed in the 3.9.2 release notes:

• Make the Global Options for PHP also target dependend

Can someone explain what this covers? Is it everything under Globals? Or certain things like DB connections and Security Providers?

If it is everything, can the reasoning be shared? I use Global steps to perform standard steps available to all API files. If I now have to duplicate changes I make across each target, it seems like an extra overhead and don’t understand the benefit. It could potentially also provide a point whereby a working dev environment would not work when sent to production should a change not be made to all targets, by mistake.

I completely understand that DB connections/Security providers need target specific settings.