Can instance config inherit(append) from profile or common configs

I am new to here
I know there is stack profile and config would inherit the profile

But if there is a field which is set in the config then it would complete overwrite the parent profile settings.
Is there a way to append setting, for example I can put group idmap settings in the profile then set the uid idmap in each instance’s config

Now I have to copy it from profile, after pasted them into instance config then append it