Hi,
Is there any particular reason why you want to do so? (Optimization Level = None (-O0)).
Regarding the "automatic placement of Flash Configuration", it is not recommended to disable the automatic placement, unless you are fully aware of the effects of this.
An alternative solution for this, is with this modification: (in the file startup_mkw38a4.c)

With this, the compilations work. And the Flash Configuration will not be impacted. Can you try it?
Best Regards,
Ricardo