AC Condensate not draining from newish HVAC
If the drain works with water poured in it it is clear and his professional opinion sounds correct. If the water did not drain or there was water damage there would be a problem. My guess at this point is the new system is a higher efficiency unit with a better balanced evaporator so it may not produce as much water as a less efficient model. The big difference in newer units is the evaporator is not having the extremes of cold that creates more condensation due to the larger temp extremes of older units but creates the same btu's per hour by managing the Freon usually with a temperature controlled throttle valve where many older systems used a simple orifice. The throttle valve is a better way to keep the evaporator at a constant temp where the orifice has no feedback ant the evaporator temp gets colder while the compressor is running. This may be the reason you do not see the amount of water due to the tighter control.