Well spotted..... very often photo shooting and testing go hand in hand and in this case whilst photo shooting I was testing a board with an airex core and carbon layup - not the usual full wood core. The results were actually quite good until about 10 mins after this when the board snapped in half
The Jackson has a composite core, paulownia, poplar and airex but airex in the NON critical parts (like the nose). Bench testing shows it's around 45 % stiffer than El Stubbo with the carbon foil plate attached.
Jackson is a dedicated foil board and has chined rails to increase rigidity without simply adding glass or carbon (which add large amounts of weight too). El Stubbo is a cross over board that can be used with or without the foil and as with everything in life with compromise comes....... some compromise!
Aren't shinn and zeeko both made in Poland? I wouldn't be surprised if the shinn masts are made from the same extrusions as zeeko.
Given their recent collaboration, I'd say you are probably correct.
as far as I know Shinn was together with Nobile before, Nobile makes Boards for a lot of Brands.
Nobile was a board factory (I think also for snowboards ...) already years before the were an own brand,
so they have great experience with board building especially twin tip cunstruction methode.
I think the strut Shinn / Nobile is also the same...why not...