First of all let me say that I absolutely love Japan Airlines and often use them even if they are quite a bit more in Economy versus other Airlines. Just can't beat their Economy Class product on on their 787, 767 and even the 777.

I am working on a trip later this year to SE Asia in Y and my question is, is it possible to book a certain fare class which allows seat selection in advance (it seems Q and up and even N now) on JAL.com?
I think I know the answer but wanted to ask anyway. I like to reserve seats in advance because at online check-in (24 hours before departure) my experience in and out of YVR has been that there is not much left to choose from and I rather pay the extra but the website doesn't seem to allow to choose a booking class where this is possible like other airlines do.
It seems that you just have to look around and try different options or work with a travel agent who can enter specific booking classes.

Maybe there is an insider trip I don't know about yet.