Just make sure not to get any muzzle break that is specifically advertised as a flash suppressor.
I use a Primary Weapons System TTO on my featureless rifle. It makes a large enough difference for me on follow up shots that I went that route again for my second carbine.
It also is well on the safe side of not being classified as a flash suppressor. It doesn't have any tines in the front so it shouldn't attract attention.
I did notice a significant rise in muzzle blast and loudness. Nothing you can't get used to but if someone was shooting close enough they might be annoyed or enjoy it