There's plenty of examples of people recognizing opossums as a great ally in controlling tick populations (here's one example). However, I can't find any examples of opossums being intentionally released or supported in areas specifically to control ticks.
Have there been any efforts documented that deliberately increase opossum populations to reduce tick infestations? If no, are there specific reasons why this has not been done? For the latter, there are of course examples of biological control gone wrong (e.g. cane toads released in Australia), but that doesn't seem to deter all biological pest controls (e.g. nematodes to control fungus gnats).