Newly added config blocks aren't executed after the ending of config phase, the same applies to other app methods because they result in additional config blocks internally.
It is possible with:
app.config(($provide, $someProvider) => { $provide.value('$someProvider', $someProvider); }); app.controller('someCtrl', ($someProvider) => { $someProvider... });
This voids the warranty and may indicate XY problem that should be solved the other way, depending on what $someProvider is and how it functions.
If $some is injected and used before setting $someProvider, this will result in race condition. If $some was changed at some point to not watch for $someProvider properties after instantiation, this will result in breaking changes without notice that will make the tests fail.
It is acceptable for badly designed third-party services that don't cause ill effects when being treated like that. And as any other hack, it should be thoroughly covered with tests.