I finally received an answer from Salvimar. This was my question
Quote from DanWhat is this thing inside the footpocket slot on the bottom that doesn’t allow me to push the blade into the footpocket?
This is the answer I got.
Quote from SalvimarHallo Dan,
I don’t understand wich problem do you’ve: inside the the slot there is a wall in the middle to couple with our blades, but standard blades don’t arrive to touch this wall...
You can fit easily every kind of blades on our footpocket.
Let me know, regards
Looks like Larry was right. Whoever's using the Salvimar footpockets with standard blades is simply leaving them at the tab. I guess I should've taken a picture of the fit of the blades inside the footpockets before I threw them out, but it's too late now. To give an idea the tip of the front lip of the footpocket barely reached the angle of the blade. For contrast here's a pic of the H Dessault footpocket with the new Speardiver fiberglass blade. You can see the front lip completely covers the angle.