One of the worst things regarding this game's combat for me has to be the input queuing on controller. For those unaware, this makes inputs entered while already executing an action slightly delayed, so that they'll occur once the current action is complete.
If you want to test this easily, use a semi auto weapon that fires about 1.5 times a second, like the Aklex Prime. You'll notice that many inputs entered with the weapon's weird fire rate don't go through, and to maximize your fire rate you need to time shots more carefully. Another example is the Prisma Obex, where spamming the trigger just makes half of your inputs disappear.
Weirdly, there seems to already be larger input queuing with some melee weapons and abilities. Protea turret spamming and Tonfa combos are examples of this.
I'm not sure if input queuing is tied to attack speed or even specifically set, but having some options regarding these would really help controller out. I'd say that Controller parkour feels extremely fluid, but the gunplay is definitely lacking compared to mnk. Would like to hear thoughts or reasoning regarding this.