AJ133 Replacement Engine Misfiring Cyl 1

Replacement engine for 2018 L494 Land Rover Range Rover Sport 5.0 Supercharged Dynamic exhibiting problems minutes after being returned to me post engine replacement.
Engine replaced at under 6k mi, 3.5 months after taking delivery.
Pending faults indicated a misfire condition on cylinder one. Driving experience was akin to randomly jabbing the brake pedal (while accelerating), most harsh at lower RPMs.
Dealership diagnosed a failed auxiliary coolant pump, which is also suspected to be the cause of the original engine's failure. Hopefully the 3-5 hours of mixed low-speed and highway driving hasn't already caused damage to renewed parts. Heat damage to unrenewed parts is unknown at this time.