Steve,
The thing is, that Annie probably won't be "voyaging", as she and I understand the term. SibLim is configured as a coastal cruising boat, with the shoal draught keel that Annie has got made. More important than self-righting during an ocean storm (Beaufort storm F10, which implies winds in excess of 50 knots and wave heights well in excess of 4 metres) is the ability to creep up into the mangroves when such conditions are forecast for New Zealand. A routine gale is a different matter. I don't have any qualms about SibLim's safety in an inshore strong breeze-to-gale situation, Beaufort F6 - F8. There, the seas are below 4 metres, and there is little danger of knockdown. And if Annie does decide to go on a trip up to the Islands (Fiji, Tonga, etc), it would be undertaken during a good weather window.
But some people who have expressed interest in the design have said that they want to cross oceans. In which case, I have said that the keel ought to be deeper, to lower the CG and ensure a greater angle of vanishing stability, AVS.
Having said that, it is possible to voyage safely in a vessel of shoal draught. I did it, in Tystie. In 85,000 miles I never encountered Beaufort F10 storm force conditions in the open ocean - it's rare, unless you go into the Southern Ocean - but in Beaufort F8 and F9, gale and strong gale, she felt safe enough, with careful handling. She is CE-marked as being in category A, ocean, and has an AVS sufficiently large to recover quickly from knockdowns. It's not only about deep draught, it's also about a number of other factors in boat design. The link you give to an older form of lifeboat shows a type that was self-righting because of the whaleback design of the deck.