I'm coming back to serious raiding after taking a break from pre-mop era.
Basically, what I'm trying to figure out is which spells update dynamically (each and every tick/hit/etc calculates its damage based on your current stats) and which update via snapshots (i.e. take a snapshot of your stats at the time of casting and keep that value for the duration of the spell)
I'm interested specifically in AMoC, SrS (specifically if it updates dynamically, or snapshots at each CS refresh), Dire Beast, Stampede, Black Arrow, and Explosive shot.
As a general rule dots(AMoC, SrS, ExpShot, BA) are snapshot. As far as Serpent sting refreshes with CS, I'm not 100%, but I would imagine it updates with each refresh(otherwise you would use it with all trinkets and then never let it fall off).
Pets/Guardians update dynamically. Stampede, DB, and the like.
SrS is snapshot, but refreshes the snapshot every time you CoS, so it's "effectively dynamic". AMoC, DB, Stampede are dynamic. BA I'm not sure but I have a feeling that it is dynamic, I just don't play SV in non-explosive trap situations enough to recall offhand. Explosive is snapshot, but it's such a short duration DoT it's effectively meaningless. If you fire off 3 in a row and your trinket procs inbetween 2 and 3, ES #3 will be updated, and the ticks will be rolled into at a higher level than the previous ticks on #1 and #2.