Whats best for this rust hole in frame

From that picture I don't think that hole goes into the body. You can remove the inner hatch panel to see or stick a screwdriver in to see if it contacts anything. That is a common area of rusting on the Escapes. The passenger side usually will rust first right through to the inside and the shock mount will push trough into the interior. Dorman sells a patch plate that can be welded into that area on both side, it is so common.

Start saving for another car as this one is on its last legs.

Im having piece wleded the autobody said would work