I have not but I once looked into doing the same thing. It starts with a class 3 front trailer hitch. I believe only class 3s are sold.
CLICK HERE to see one I found in a flash.
CLICK HERE for the details on the manufacture website. I would reach out to the manufacture to confirm it mounts properly to your model year E350 or E450. For it to fit, your Ford front cannot have an additional lower skirt like we have on our 2007. I could cut a hole but that was a detraction for me. Also, there may be interefereces to an upgraded stabilizer bar and/or steering stabilizer.
A front hitch is popular in boat launching as well as for bicycles. It is also a great attachment point for a tow hook when pulling out someone who is stuck. And the same goes for yourself. You can be towed out from being stuck.