As a level 6 character (1 fighter/5 warlock) with 16 dextery and using a rapier/shield/scale mail and Defense Fighting Style (19 CA, up to 20 with a half plate), which one of those feats would make my character less likely to get hit against 4 attacks with a +5 bonus to hit/turn?
I'll be the party's tank and I intend to fight using the Darkness + Devil's Sight Combo as often as possible so most attacks will have disadvantage against me, Booming Blade should make anyone think twice before moving away from me.
With the Medium Armor Master I can have a constant 20 AC with just a scale mail, while the Defensive Duelist would allow me to to get a constant 19 and use my reaction (which is wasted most turns otherwise) to get 22 against a single attack per turn.
I know this is a question with quite some math involved but I hope it won't be closed. Thanks in advance.