Yes, the adaptor is made... I had one on my boat years ago. And I used it for camping, as a 20 # propane would last for weeks driving a camp stove while the throwaways were expensive and would only last a couple of days.
There are a few different types of connectors. There is a connector called a "Quick Connect" I've never used one for LP gas but I believe there is a hose made to fit it with a standard "Throw away" cylinder "head" on the other end of the hose
There is a hose that is intended to go from one of the new OPI portable tanks to a grill designed for use with disposable bottles