The APL dumps CBs with either trinket proc or the ring proc, or if it hits 2.5 embers regardless of how soon it's about to dark soul.
There's times when it has literally no procs at all with like 15 seconds before a dark soul that it hits 2.5 embers and casts a CB, and then gets say just the crit trinket proc which is less crit than DS and casts CB... which means it has no embers for the coming DS.
So in other words it's not perfect, like I initially said... Which gahddo apparently takes very personally, because I guess he thinks it is perfect or something.