Rather than taking an advance that most will never pay off, take some money out of your back catalog or prior work and fund your next music project yourself. Or at the very least, hire a good mix producer and do some real mastering of your music.
The mixing process can tighten up a vocal performance, make a piano feel more emotional, make a whole song sound more indie or more pop. These things are achieved using technical and creative psycho-acoustic trickery. Mixing engineers are alchemists. Song colorists. Their trade comes with years of education, practice and talent.
To the industry, an EP is considered a demo but can lead to much more.
The song has to be recorded in the highest production value possible for the genre…before it can be pitched for use in film and TV.
I have all the tools and gadgets. I tell my son, who’s a producer, ‘You never work for the machine; the machine works for you.’