i notice that my unit of the CCR, the main is louder than the aux, is this normal? Anybody has same issue?
what does ‘/system health’ report when you set AUX as main?

another thing is if i put 2-3 fingers (~1-2cm from the fan) blocking the air flow outside the casing, the fan seems can sense this and speed up.. or is it just my imagination??
Possibly because you block the airflow
I would like to know what the performance of the router in NAT mode?
I would like to know what kind of router performance MikroTik CCR1036 12G-4S mode nat? Whether the router is able to skip 5Gbps traffic?