I use a piece of spectra that has a bowline tied in it that will fit through a standard bullet block then goes to a "quick" release D shackle on the side of the mast.
Yes, I saw that in your pictures and it is the fastest quick release setup so far.
By the way. Wouldn't it be smart for all of us to get a "user gallery" on the
www.formula16.org website and show our tweaks and modifications there; as some others have already done.
That case we don't have to rehash these things in 6 months time and then again in 12, 18, ...
Example :
Link to user specific galleries on formula16.org Wouter