You need the unit APP rating to validate your license, the APP rating must be part of your license, part of the unit training plan and so on.
According to your AIP, is the APP service provided or not in your airport, if not what you are doing is an abuse.
However, back to your question, and if what your are doing in that part of the planet is legal, during the coordination you have to reach an agreement with the ACC, you are entitled to go out from the standard (LOAs) and go for an earlier release, even out of your jurisdiction area, that's called airspace delegation.
But yet, an APP controller can do what I stated above, a TWR controller is not supposed to, you should normally take control of traffic when established on the final track of an IFR procedure .