Hi Pablo,
Thanks for reaching out to us.
Substance Painter has many baking parameters to get a normal map as clean as possible. It is not very clear what is precisely the problem with your map, but I am confident you will get what you want without going back and forth with Photoshop. I would personally check first my cage distance and make sure I don't have any matching error (red areas).


(if you want a more visual help about our new bake mode : https://www.youtube.com/watch?v=hYtHp4IXvsM&ab_channel=AdobeSubstance3D)
And if you need something very specific, you can always paint on a layer on top of your normal map inside of Substance Painter, but it is not something I would personally recommend.
Please, do not hesitate to contact me if your problem persists.
Have a nice day,