The driver is rated based on max voltage output. Do you know what forward voltage of your cob is at 1.4 amps? I assumed they were 52 volt vero, but they look like they would be more like 70 volt C version. 70 volts x 1.4 amps Puts you right about there.
Did you use a kilawatt to measure them? Also, if you’re using a potentiometer to dim with, opening the dimmer circuit will give you a little boost in output, up to 108%. But you have more light than you need, so I wouldn’t worry too much about it.
Your Temps aren’t too bad. Probably a tad higher on the floor because there’s not as much air moving there. But you should be plenty good with mid 70’s at canopy level I would think.