The issue which I see is the same as all the others, the low pitch. I wonder if you flared the top of the king post getting the struts up as far as you can to the ridge, in effect increasing the pitch a little. In Historic American Roof Trusses there is an example of a 32' king post, set up the same way, with a 12/6.64 pitch roof. I can't find a pdf for it, but in the book it is on page 38, fig.4-6 In other examples metal straps were utilized.
What is the pitch on this car park?
