If you wanted to suggest the Whonix project using Kiwix for creation of offline documentation the answer is no. Assumption:
I am operating under the assumption that Kiwix is a free in price service but the service itself being nonfreedom software. No source code available for public. Whonix project couldn’t run the code by itself and use that to generate offline documentation. It would have to rely on remote web service. Happy to be proven wrong on that assumption.
Trust: Whonix documentation is too comprehensive to trust any third party or any remote web service with offline documentary creation. It would be hard to check if any malicious advice was injected into the documentation. This doesn’t even need a malicious operator but another third party having compromised the web service would lead to the same issue.
Software Freedom: Whonix project as a Freedom Software project shouldn’t depend on a third party nonfreedom software web service.