In Xcode's build phases section is it possible to enable/disable compile flags bases on scheme

If an Xcode project has some compiler flags set in Build Phases / Compile Sources, then is it possible to have those enabled if scheme A is selected and disabled if scheme B is selected.

Same question for things in Build Settings, such as Other Compiler Flags.

I suppose it could be achieved by having two targets, one with things enabled and one without, but for a very large complex project, duplicating targets is not necessarily an easy thing to do.

I.e. if a flag is set here:

Anyway to turn it on off without having to duplicate the target?

In Xcode's build phases section is it possible to enable/disable compile flags bases on scheme
 
 
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