A lot of the controversy I can find on the topic of pterosaur wings is in the shape and attachment of the back of the wing to the hind legs. However I would like to know more about the part of the membrane that stretches in front of the elbow. Though I can find much about the controversies of the pteroid bone, I can't find any in-depth information about the attachment of the membrane to the body itself.

Are there differing theories as to where the front membrane attaches? Most pictures and diagrams seem to indicate attachment to the shoulder or just above it without explaining. Is it possible for the membrane to attach farther up the neck? The head? The crest? would the membrane stretch out to take up the maximum amount of space, or would it be narrow with a sharp bend near the neck running almost parallel towards the end of its attachment. Are there aerodynamics involved that would make this entirely unfeasible or particularly advantageous? Perhaps a large forward membrane attached to the crest could provide more or less kite-like lift simply by moving the neck up and down? or maybe the drag of it would make the creature drop like a stone? I don't know enough about the specific mechanics of flight to intuitively understand how any of this would work, so maybe that just sounds like a really stupid idea to someone who does understand, but my point is: has there been and interesting or compelling theories or experiments regarding the attachment of the front of the membrane instead of just the back?

This page has a good summary of where we're at:
https://pterosaur.net/flight.php