Suppressors actually increase back pressure, and will not generally have any effect on piston or gas ARs. Some platforms like roller delayed HKs will require a part swap to make it work. If anything, an adjustable gas block or different piston setting can be helpful to keep the gun from beating itself up and forcing gas back through the ejection port and charging handle. 9mm ARs are blowback weapons and usually have a heavier buffer and spring, so you may not have to adjust anything at all. Feel free to send me a direct message and I’m happy to go over options with you. I have suppressors on the number of my guns including the specific model you are looking at.