Flexible Blast feels like a class feat tax for the class

[singingzombies]

But having it built-in feels a bit too powerful for the class as well to allow this martial to use melee and range attacks off a single attribute. Also a lot of the existing base class features feel essential so I wouldn't know what to swap with it if it was to be built-in.

This is just feels a little close to the Alchemist's Powerful Alchemy situation and it's always a little awkward when there is a Level 1 Class Feat that stands out among the rest.

There's also the potentially strange interaction of Flexible Blasts working with Elemental Weapon to allow for a Brutal One-Handed Crossbow or a Brutal Firearm but that is possibly intentional since the damage die of Elemental Blasts with those Ranged Weapons were similar anyway.

[RexAliquid]

Flexible Blasts is nice, but by no means necessary for every build or element. The finesse elements can easily go without Strength, and the others can manage going either way.

[Guntermench]

It's only a tax if you want to go Omni and stick with one attacking stat. Or pick Dual and grab 1 STR 1 DEX.

[PossibleCabbage]

Honestly, I thought being able to use Str for both melee and ranged is an incredibly powerful option for a single feat. Like fighters wish they had this.

[aobst128]

It does seem like a tax if you're using earth or water that would otherwise have 2 stats you need to switch hit. Earth being propulsive is begging to max your strength too.

[YuriP]

IMO it's just OK feat. Let's look it as a whole.

We have to remember that almost everything has Impulse trait and that Impulse trait means risk of suffer an AoO when too close even using melee Strike option and as ranged attacks by default uses Dex to hit not matter what element you use.
Also as a light armored martial, dex is basically a must have stat unless the player intent to have Sentinel Dedication or to massive use Assume Earth’s Mantle (but yet you still need to find ways to survive with a low AC).

So in practice if a Kineticist want to focus attack at range (I believe the mostly due AoO risks) it will have a good investment in it's Dex, so Brutal isn't that thing at range in a char without a heavy armor and at melee only half of the elements already have finesse trait. Also I expect many players making a 16,16,18 str,dex,con Kineticist easily making this feat useless.

IMO this feat will probably works better for a future Kineticist Archetype then for the main class.