I think their definition and ours of "large" might differ. I suspect they would not even switch the machine on for less than 10,000 oz.
That's why its not really very profitable to load up on lunars until the 300,000 limit for 1oz are completed. The 2,5,10 oz sizes are much safer numismatically because of the fact they SAY they dont mint any more of those beyond their year of issue. The kilo sizes are probably not a good idea to overpay on for past years as they are also subject to being produced over and over during the course of the series. So wait it out for the kilo sizes which should become available again if the demand increases as it probably will.
I found the kilo coins are much harder to source. I recently paid quite a hefty premium for a 1kg lunar tiger bullion coin..
They are theoretically unlimited in 1 kilo size and future years will bring opportunities to get them, but at what price? Perth mint has done big job lots of the 2008 kookaburra for example and about 6 months ago did a huge lot of 1oz mice. You do see this from time to time. I just lock in my price by buying the whole 12 kilos for example required for the set and buying the future ones with a view to selling the earlier acquired kilo. So I have 8 kilo coins standing in for the future coin purchases.