Any advice to the Simon says step on ZiS?

The fucking hit boxes on the radios is atrocious. I can get through the seti coms no problem, and i play solo so I can write down the color patterns, but I can't ever do it quick enough because the hitboxes are so bad, so I constantly get brutes that make me waste ammo and get cornered. I usually have the upgraded Kendall 44, shredder, and perk insured on. Any suggestions to boss fight strategy or my loadout?