Can I use the LED drivers at full load continuously? Most of the AC/DC power supply are suggested to use at 70% load.

LED Drivers are recommended operate at full load as long as it observes the working temperature specified in the datasheet, which means Tc measurement results should be equal to or less than the stated Tc in the data-sheet. 3 years warranty complies as long as drivers operate within working Temp and Tc. Limit as well.