Yes, I did see that. You are right, CHAD (CHeap And Dirty, for the novices) staging is an exception to the rule. I theeeeenk it requires either intrinsically heavily overstable rockets or a lot of nose weight. I still think people should aim a little higher than the minimum standard rod exit speed for staged birds, if for no other reason than the stakes are higher, especially for black powder staging. The FarSide, MicroSonde, and Commanche are more typical three stage birds and employ a LOT of fin surface area. The Lil' Augie is a cool CHAD stage design that doesn't have overly large fins.
You get a bit of rod whip or a puff of wind on a single stage bird and maybe it goes cruise missile, still most likely will have ejection event IN THE AIR, so while anything can undergo fecal turbine interaction, the most likely bad events are a zipper, a long walk, or a lost rocket.
A STAGED rocket goes cruise missile off the rod, there is a good chance it may come to earth BEFORE all motors are expended. Chance of a fire from a lit motor landsharking the rocket on the ground is higher.
I love black powder staging. The biggest down side from a safety issue is that there is no "tilt" or other stage ignition cancellation mechanism. Once the bottom stage lights, the probability that the upper stage(s) will light is pretty high REGARDLESS of the attitude or altitude of the rocket. So I tend to push toward being conservative on getting that stack off the pad with authority (good robust motor, as you recommend), and for first flights going conservative DOWN with wimpier motors in the sustainer and and mid-stages.
My experience has been that while many rockets fly straight up right to apogee, if they START to weathercock that almost always progresses with altitude, and barring some REALLY cool electronics I have seen on the Staging forum (I think only with high power rockets) weathercocking RARELY corrects.