Generally speaking how does one do that?

Presuming that said person received the NDA, said person would have the contact e-mail from WK for the project.

That said, I would advise using that e-mail address to send forth their question re: potential conflict of interest.

If you mean how does one contact WK in general, I would say it depends on the nature of the question/contact.

If it's to inquire re: the Beta Test process, the instructions specifically request that folk do not do so. If it's another sort of question, I would advise PM'ing Ziran here on the Realms. He's on pretty regularly.