Here’s basically the stat breakdown for ele;
Crit: It’s a whatever stat, doesn’t scale with anything in the kit besides Ascendence iirc.
Haste: Lowers GCD, makes flame shock ticks faster. Generally just a feelgood stat.
Mastery: Unless you can get to 100% there’s effectively no way for this stat to be ideal. If you got to 99% but never procced it, you’re just wasting stats. It’s exceptionally good if you go for the one shot cheese build, however.
Vers: Your baseline PVP stat.
Haste DRs after a certain point, just like mastery. Though I believe mastery for specs like ele DRs after like 85%ish or something, rather than the standard around 5k(?) iirc. Having your globals be smooth is VERY important in PVP. Also more flame shock ticks = more lava burst procs = more maelstrom = more earth shock = more lava burst. It’s a rotating CD in a sense.
You could voice this question exactly the same to boomy players, and we’d say basically “Faster casts, more globals, dots tick faster [even if the damage isn’t stellar]”. It’s just a good stat for getting your DPS flowing, even if in an ideal world full mastery makes you do big dam.
It’s not really about the procs. Ele shaman is all about spamming damage.
When you have high haste you get 100s of more damage globals off per game which is really important on a spec like ele that never has downtime on damage globals
There’s no real threshold or breakpoint you’re looking for.
I’ve done low haste high mastery, vice versa and everything between in multiple eles and I’d always end up at my skill level either way.
Ele is really a gcd locked spec tho, the shorter gcds makes the gameplay bearable. Whatever the tempo you’re comfortable with is where your haste will be.
Especially with this tier and getting stats from splint elements and ele blast you can play lower haste and game around mastery making as procs lethal and getting more primordial resets via rolling magma.
I wouldn’t over think it, jus play with as much haste as you feel comfortable with.
High mastery can sometimes outright end someone on asc procs…but you’ll be a slug getting there since asc chance ramps per lava burst that lands (not overloads)
Here are some things to consider/test for yourself on what feels best for you.
Mastery - this is basically a better version of crit for ele shamans when you consider that crit is + 50% damage and mastery is +85% damage. Now, of course, crit is buffed for ele shamans but requires a lot more of secondary stat allocation to achieve any respectable number, and really would only benefit earth shock and healing. Mastery also has the added benefit of further reducing primordial wave cd which is basically your best dps button. Downside is basically this is just a lava burst stat.
Haste - there are certain thresholds to consider here. At around 22% I believe, you shave off 1/10th of a second from lava burst cast time (I believe from 1.7 to 1.6). I think you can get this down to 1.5 in the 30’s, but that may be a lot of stat to sacrifice IF …
You are already getting the lion’s share of benefit from haste. Take off your gear and apply a flameshock to the pvp target dummy. Check how many ticks of flameshock you are getting per single application. Then check again at whatever haste thresholds you want to check. It is entirely possible you may be getting one or two additional ticks per flame shock application from, example, 5% haste to 25% haste.
Find the balance between the two. If you can get to a good haste value and muster 50% mastery, you’re basically doing 147.5% lava burst damage per global, while also proccing a ton of cdr on prim wave. Careful not to sacrifice too much haste because if you’re not proccing instant lava bursts then you can’t proc mastery anyway, and you would rather proc a 100% lava burst than an 85% one, albeit without the global, if you had to pick between the two in a practical setting.