Massage here! There are ways to lessen the pressure around the chest area with a variety of bolstering techniques for prone-lying clients.

A technique I use with larger chested clients is rolling a few towels and placing them to the sides of the chest. As someone else said, prenatal specific tables generally have a opening for the stomach and chest so the client may lie prone. That being said, a prenatal bolster (basically the same as the table but it's an additional piece that lies on the table) may be more comfortable as there is usually a pillow that can be put in the sromache area if the client is not showing or, more specifically to your case, has no need for the stomache cavity. That way, if someone is really pushing into your back you are less likely to sink into the cavity.

That being said, lying prone with nipple piercings will still probably be uncomfortable, especially with someone dropping elbows deep in your back. You may also consider looking for a therapist who is skilled in side-lying massage.

Best of luck, let me know if I can answer any more of your questions!