After experiencing all these issues and a few close calls, I replaced the rollers on my stands with a slippery tilting top. The pivot point is slightly off center so that the top tilts downward on the infeed side of its own weight. This prevents the out feed piece from catching on the leading edge (how many times did that sagging out feed push the roller stand over!) and eases it up and over the support. The table then is level with the machine table and safely supports the out feed without introducing directional bias. Overall, it is much more stable than the roller or ball situations.
It is ideal for small shops that cannot afford the luxury of a large stationary out feed support behind their table saw. This support can be moved quickly to another machine where if used with a mate can perform infeed and outfeed support.