I agree on this. KYC should be announced before the program start so as to give a heads up to participants that it will be implementing one. Also, this is in consideration of the security risks involved for the participants who will give out their KYC information which is usually confidential in nature.
This is all, of course, correct. To declare that the KYC will be checked only at the end of the ICO, it is a fraud, a fraud, to a certain part of the participants who for various reasons do not want to pass it, do not pay the tokens they earned.
However, it is also necessary to take into account that the requirement to pass a KYC test in respect of participants in the ICO generosity campaign is generally illegal. No document explicitly requires that such an audit be conducted for members of the ICO generosity campaign. We are not investors and therefore such an inspection against us should not be conducted.