Going through the KYC is not a big problem in itself. And in the case of freeing bonuses, it also seems realistic to me that Fortunejack asks for verification, especially because it concerns free spins. Otherwise, it would be very easy to create different accounts via a VPN or similar technology and thus convert free spins into money. This is then covered with the KYC. It's nice that Fortunejack gives away free spins, better than a deposit bonus in my opinion.
I can agree on the whole of this post. KYC does seem intimidating but when its demanded from a trustworthy gambling platform like Fortunejack, then I think its a much better alternative than to doing KYC on some other, new and unexperienced casino.
Free spins can still win money, and the flow of money is what is regulated, not the registration of an account itself. I would advice against using VPNs, they can be detected and you might encounter problems with VPN-unfriendly platforms in the future.
KYC in itself is supposed to protect the casino legally, because it needs to follow regulations and it also protects the client/customer/player legally, in case there is a problem you can always prove the money is connected to your person.