Why not Crit Chance mods? [Convectrix] has an extremely low base CC of 16%. [Critical Deceleration] boosts this by only 32% to 48% final. Puncture procs at 5 give a flat +25% cc boost to 41% final, which is almost similar to what [Critical Deceleration] gives.

If external fire rate eg ability, Arcane Tempo or [Reinforced Bond], could drop [Shotgun Barrage] for [Primed Point Blank] or [Vigilante Armaments]

If using Viral primer, drop Viral mods for [Primed Point Blank] + [Vigilante Armaments].

If no Shotgun Vendetta, just use Primary Merciless.