I think you should just go with gloss and keep it simple, its too much of a pain in the ass to try and not get the bay to gloss over. Cleaning up oil and dirt over time will rub away the matte effect and eventually a sheen will start to pop up in well used places.

Factory engine bays are cleared, its just not buffed or cleaned up from factory and after all the dirt and grease it gains over the years it looks flat but if you degrease a bay it will turn shiney, its dull but its still gloss not matte.