But might not the OP face a real problem with lack of award availability for changing dates?

Anyway, the only thing I'd add to the discussion is to not bother with Jakarta if you're going there for the city itself or as a connection to Denpasar/Bali. You can fly directly to Denpasar from other cities, I believe including Bangkok, Hong Kong and Singapore. Of course, if the point of going to Jakarta is to visit other parts of Indonesia, that's another matter.