I wouldn't expect your alkalinity to drop to catastrophic levels if you dosing container went dry because of the factors affecting uptake that Randy mentioned. My concern was if you lost power to a system that provides flow, lighting, or heat to the tank and that caused a drop in coral uptake of alkalinity. Like if you were out of town and your lights didn't fire up for 2 days but the dosing system continued to make up for 7dkh loss each day. You have a recipe for a massive and rapid alk spike in such a situation. Have you ever had something like this happen where your corals slowed their growth and you noticed a rapid alkalinity jump?
I haven't had that happen however if it did the Apex controller would shut it down. The Apex is set to kill the outlet and send text message if PH set point is breached. I have it set to pH > 8.35