if the saddle fit is correct, it wont be once you put a bulky pad like that underneath it. If I were you I would look into a thinline pad. Im actually selling one if you are interested. I can't use it anymore because my horse likes her saddle fit to be extremely narrow and im not supposed to put anything extra, even something that thin, under it. You can PM me if you are interested.
I am going to speak with my instructor, and see what he thinks. Thank you for the info! I don't know what he will recommend I purchase so I don't know if I should look into a thinline quite yet. Thank you, though!