thanks for the replies everyone!
I arrived around 4 hours before departure and indeed the counter was open for an "early check-in". Though that said, only one counter was open and it was swarmed... There are no priority check-in counters at this time, only for them to open at T-3 hours. The queue was around 1 hour long and I ended up sitting by the Coffee Bean Stall waiting for an hour just for the Business class counter to open because there was no point in waiting. The J counters ended up opening T-3hours 15 minutes.