It is one of those things that bugs me, by default Gimp remembers the last-used settings. Made for experts who take more than one session .
Since Gimp 2.8 I set up Gimp the way I want, then go through those Preferences un-ticking save-on-exit and clicking on save-settings-now. Then when I start Gimp I know the settings.
I think the default should be the other way around but that is just my opinion.
For a dynamic like Basic Simple you can not change the settings, it is a default Gimp system file and is not editable. Make your own dynamic if you want a custom version.
Since Gimp 2.8 I set up Gimp the way I want, then go through those Preferences un-ticking save-on-exit and clicking on save-settings-now. Then when I start Gimp I know the settings.
I think the default should be the other way around but that is just my opinion.
For a dynamic like Basic Simple you can not change the settings, it is a default Gimp system file and is not editable. Make your own dynamic if you want a custom version.