I am *not* a lawyer, but in such a situation, I'd suspect I'd want to cover
my rear end with boiler plate and be able to show proof that the
installation is guaranteed, by someone other than myself, for winds higher
than have ever existed in the area.

A "Professional Engineer" can do that, if he signs the paperwork
and adds his license number to it. But not all PEs will do
a tower, as any guy not familiar with towers is not gonna risk
getting their license pulled.