First, a disclaimer: the Shaman trees for Dragonflight are absolutely brilliant. This thread is about refinement to a tree that’s in otherwise good shape. Great job Nimox 
That said, I think Magma Chamber and Searing Flames could use some touching up: the positioning of the former, and the overall power level of both.
First, Magma Chamber’s positioning. This is where Searing Flames formerly was, and was swapped as part of the August 2nd build. The idea was that, with Windspeaker’s Lava Resurgence now a choice node with Skybreaker’s Fiery Demise, Searing Flames felt lackluster as a single target talent. That’s true! But unfortunately, so does Magma Chamber. While the numbers do contribute here (Magma Chamber averages out to 2.1٪ damage increase to Earth Shock per point, which is a tiny impact), the design of the talent, and of any talent triggered from Flame Shock damage, is such that it will always be at its weakest in a single target scenario.
In the situation where its numbers are so big that it is impactful in single target, it becomes out of control in multitarget - ultimately, it’s just a design that isn’t suited to single target and feels a bit like a tax to get to the high power of Windspeaker. “Tax” talents like this are somewhat unavoidable in trees this size, but they do feel particularly bad when they occur in the bottom third of the tree - the most points-restricted and highest impact part of the tree. Optimally, every point you spend down here feels like its own payoff, never a point you need to spend just get to the payoff.
Secondly: the strength of each talent. I touched on this briefly with Magma Chamber, but both of these talents feel undertuned for nodes in the bottom of the tree (comparing strictly to other Elemental talents). There is a challenge to making these sorts of talents that reward good Flame Shock spreading strong in 1-2 target scenarios without making them overbearing at higher target counts, but I think Searing Flames demonstrates a partial solution in positioning: gate them behind weak single target talents.
In this case, it is deeply unlikely you are taking Primal Elementalist in any single target scenario in Dragonflight. Similarly, if you are taking Primal Elementalist, you’re probably always looking to path to Skybreaker, so Searing Flames is a natural pickup and does feel pretty okay, although still underwhelming, in multi-target scenarios. So: how, then, to apply this to Magma Chamber’s positioning and buff Searing Flames to feel appropriately strong?
Combine them!
We saw in the merger of Flames of the Cauldron and Flames of the Firelord that this can be a good trick to turn two lackluster talents into one good (if situational) one. Something similar here may work. 1 maelstrom, 0.7% spender damage (or 1) per point feels a lot better than either on its own. This suddenly feels like a good funnel/cleave node, one you want to pick up for its own sake and not just because a great talent is on the other side.
This does create a new problem, though; what goes where Magma Chamber currently sits? Here is where I have little useful input. Certainly a new talent is an option. Or, move Power of the Maelstrom here and make something else in its place. As many authors and game devs have noted, readers/players are generally good at pointing out things that aren’t working and poor at offering solutions. I have one idea I think is decent but I dare not push it!