To shorten the ridgeline by 3-4 inches will change the way the hammock feels. At least it has for me. That may not be bad if you are setting up your hammock too taught and having difficulty laying across the diagonal.
But if you already have the feeling you want, then use the Zing-it. I use Zing-it for my structural ridge line and it is plenty strong for that purpose.
Mine plays about a middle C when I pluck it, so it is fairly tight.