I think your best bet at this point are cultural controls from the PNW Handbook https://pnwhandbooks.org/plantdisease/host-disease/maple-acer-spp-verticillium-wilt verticillium wilt can stay active in the soil through leaves that have dropped from infected limbs and then be passed on to weeds.  If you are concerned about other trees in your landscape, it may be wise to consult with a certified arborist.  There are some preventative treatments available to them and not to home owners.  They may also know of some labs that can test for the presence of the fungus.