As an engineer of xx years, I do what the pilot asks me to do
Big airlines have safety depts full of people making rules.
I do what the airline wants.
BA always leaves the brakes ON, plus 6 chocks.
MH always releases the brakes after chocks ON. We have to be careful where we put them as they get trapped. You don't chock the nosewheels if you have a TBL, or you will have problems.
Boeings brake pressure declines with time and the brakes are not effective after 8 hours.
Airbus have a completely different park brake design and keep their pressure for ages. Overnight I see no decay at all.