To weigh in, late...
If the Neddy Seaphoon were to be developed successfully it would be the first successful CV adaptation of a CTOL jet in the West.
A few data points:
Both the MiG-29 and Flanker have been adapted for CV use. Major mods (structure, folding, high-lift) but the basic outer mould lines are pretty close. What we don't know is exactly how well they work.
The Hornet was not a derivative of the YF-17, but a different aircraft with the same overall layout. Bigger wing, bigger engines, different landing gear.
The Rafale and JSF were both designed from the outset to have CV and CTOL versions. Off the top of my head I don't remember any others.
From the early days of the jet age, the key difference between CV and CTOL fighters has been speed and controllability on approach, which drives wing/tail size and configuration. That's one of the factors that nailed Boeing in JSF - they just could not get the delta on board the boat.
Argument pro-Seaphoon: the Rafale M looks very like a Rafale C - it gets away without a 50 per cent bigger wing unlike Dave C. Seems that a canard delta is easier to drive to high lift and low speed than a quad-tail (one basic problem is that the tail on a Dave C or an F-18 is pushing down with a short moment arm while the wing is trying to push up).
Argument con-Seaphoon: There are a lot of basic Rafale features that reflect the CV requirement including overall size, landing gear location (mains and nose) and radome size/cockpit location.