Yourcontrols (and to some extent the old JoinFS) added the ability to use shared cockpits for training, sightseeing and the like. It was wonderful.
Unfortunately, JoinFS has gone the way of the dodo and yourcontrols, which still mostly works, will not share any details of the .yaml profile syntax so creating new and better profiles ends up being quite difficult. Not impossible, mind you, but with a simple text document list of what the variables in the profile do other folks would likely jump on and create a ton more and better profiles for lost of aircraft.
Personally, I would gladly pay for the software for shared cockpit and, in fact, have done so for x-plane. We need something better for MSFS.
Rick