A fresh set of ball cups, ball studs, and turnbuckles should NOT popoff under NORMAL circumstance.
There's probably another issue at hand. The most likely cause is a geometry problem, either from flexing too much (which changes the intended range) or you have a worn out or broken section of the suspension which is causing the alteration of a geometry. Also, you might want to check to see if you need limiters in your shocks, inside and/or outside the shock, depending on where the problem is, during droop or full compression.
I kept popping my RPM ballcups fitted onto AE ball studs with AE titanium turn buckles, and it turned out that the rear suspension arm was torn, but not too extreme that it was obvious. I didn't realize this until I started to wonder why suddenly the ball cups were popping off in that particular side, in that particular area for doing absolutely nothing but running the car.
A torn arm caused the geometry of the rear suspension to be altered ever so slightly, which in turn forced the ball cup to pop off on that side. Once replaced, no more popped ball cup.
But after long lengthy use, it is worth it to change out the ball stud and the ball cup simultaneously if you suspect normal wear is what's causing them to pop off. During racing, in a pinch, I used to take a plastic shopping bag and just cover the top of the ball stud with it, pop the ball cup on it, then tear off any excess shopping bag. This was a trick that I did 15 years ago, but it's a temporar fix that will eventually require a full replacement....
RIP TAP RC