It is useful to a degree, but to show current and planned hides, with circles, on the same map... I have to create an offline version of every live cache in the area. Thats a lot of typing.
Another alternative that I've been doing to see both on the same map is... instead of creating offline geocaches, I update the solved coordinates of puzzle caches in some random state I may never visit with my desired coordinates. When I refresh the map, these "solved" caches show up on the map where I want them to be, along-side the live caches.