The best wrecks have been the AT SU H motors going Roman Candle after leaving the rail then burning stove pipe on the ground. Two launches ago I saw a typical 29mm SU failure blow out the side of an ARCAS fin can, ejection blow off the cone, but then a slow yet intense burn on the pad was a bit new and exciting. Last year after one of my 24mm SU F44's blew the forward closure I gave the other one from the pack to a friend at NARAM with many warnings, he wanted to launch one in his old D Region Tomahawk. That massive 24mm composite CATO was cool, better than us usual 24mm whoosh popper BANG CATO. I don't know the numbers but the SU composites will CATO just like the BPs. Lots of factors come into play and there are bad batches of both types.
Although the BP CATOS can be really cool in a cluster, one blows and two light on the MR 171 - cool, it still flew and maybe I can get a hold that awesome video some day.
One E blows in a pod and takes the core F motor igniter with it, then the other two Es light in other the pods, not so cool but good wreckage on a PS II kitbash.
All of this has happened at club launches in a safe environment. CATOs will happen so keep your head up and don't freak out. The odds are with you.