Not a whale, so here is hoping this won't be a problem. Just in case, what amount of cash is considered "large"? Their site says 1 BTC, in European banks they frown upon 2000-3000 EUR transactions, so I'm at a loss.
And what are the documents they can ask? They asked me the id, a selfie and a bank statement to check address, that's fine I guess? Same as with Wirex for example
Well, depositing of withdrawal of funds may vary but sometimes even it's just $1000 deposit/withdrawal could end up like the others. With other's experience this exchange ask aside from KYC, proof of address, source of funds, documents of other people who give/send you the funds like their ID, take note all transaction hashes are required too and etc.
It's all in google how they scam their users asking documents after another.