What is the biggest payout that Freebitco.in have ever paid out, apart from the Lambo draw winnings in BTC? ( Is the payouts automatic or do you flag certain withdrawals at a specific amount for manual payouts? )
Given the huge profits they make, they should have a big bankroll. So, I don't think there's any limitation.
The only limitation is how much is in the hot wallets at the time. That's usually a minimum of 50 BTC when they will get topped up with another 100 BTC. If it's more than that then they just have to wait for wetsuit to top it up which will be done within 24hrs.
To find the biggest one you'll have to do some blockchain analysis on our 2 hot wallets. 3LaNNTg87XjTtXAqs55WV5DyWASEZizCXZ and 329koRvovTyNnd4ADrpR2uJHzXxfvKxta5