That's the problem for fliers - there isn't a hard copy on what rod to use when! It really is a "feel" thing! Leads to experiment and finding your own preferences! What I like may be terrible to you, what you like may be nothing like what Paul uses (REVflyer)! Partly why so many styles of rod are offered - to find that unique combo of equipment that fits your style and flying "feel"!
Don't be afraid to try any rod, at any time, in any sail - unless just totally inappropriate for the conditions, That way you might find something that works for you!!
PS: I've used black race rods in my midvent at close to 15 mph, they are plenty strong enough! Just watch your LE for excessive bend, that's your real indicator of needing to change frames or sails!!