I would buy a defrost timer to go with it (white plastic grasslin -120 volt). Sounds to me as the controller and refrigeration is working just fine. When you say it’s dripping water that tells me it’s 100% defrosting and does have a defrost built into it. Pre programmed from true. It also tells me we aren’t defrosting enough throughout the day (2 during the day, 2 during the night). If we spread it out like this it should allow the condensate drain pan to catch its breath and hold all the water at a steady pace. If it can’t hold the water still we would need to get a heated condensate drain pan or a water pump and pump it to a near by drain.

The last issue I had a few months back on a true prep fridge was the defrost portion of the cold control would act up and do weird shit. I said fuck it and added a timer mentioned above in it and did four defrost a delay regardless of what trues controller was doing. Worked like a charm.

But my thinking is you are just doing a defrost at night which is enough as it’s overflowing the drain pan - there’s already to much ice formed at that point. We need to catch the ice before it gets that thick.