why do you think 60C is too high for Asic core? i think it is very ok temps. i would be concerned if temps go over 75C. the over all airflow is very high so you just need stable ambient temps to cool this miner. "tube" design is good idea for optimal airflow. what i do is lift the back of miner so hot air escapes better, but with such airflow this is overkill anyway

i think next what is worth trying is putting rig in special liquid so all components are cooled better.