Agree with the above, you have to read your e-ticket to confirm.

Usually agent just memorize the allowance, or in other words, assuming the pax gets weight base unless your immediate destination is US. But if you remind them, they can check the correct allowance from their system.

I have once flew LHR-HKG with a ticket that touches US, and the agent simply just assumed that I have 40kg + 20kg (F + OWE), which actually works better for me because I have 4 pieces of luggage but less than 40kg. Anyway, I have re-confirmed with him that it is ok even my ticket only allows me 3 pieces, and he only became aware of the piece allowance when I ask.

Btw, last time for BKK-HKG in J, they gave my sister 40kg (instead of 30) allowance, citing that she gets extra 10kg on top of 30 kg because she is in business class.