Yes, you are right. As they stare everything on cold wallets, their withdrawals are processed manually. According to White Paper, all withdrawals are processed at 12pm GMT. Any withdrawal request submitted after the processing time is postponed to the next processing time
that might pose an efficiency failure for some users. they should be clear about this set-up to all their potential users. so being the gold standard for an exchange might not be appropriate here.
most exchanges are already having instant withdrawals. though this platform are using cold wallets for security purposes, is there other option to secure your exchange other than this? this might not attract users that are always on the go.