asking you to do KYC before you buy is straight forward and an honest way . But asking for KYC after you send them your money is kinda tricky and I do not like this way of dealing, Unless it was not planned and they kinda forced to do it which is so rare, any project should be aware and prepared before they start their ICO .
Agree, the best option is to let the KYC as optional during the ICO and later ask for the KYC post the ICO. This will make the process more flexible for both project owner and buyer