Ummm, 3A might be fine for 1S, but at 2S, power is doubled, don’t forget. That’d be like running a 1S light at 6A, not 3A.

You’ll need to bolt that drop-in right smack into the head and optimise every bit of thermal path for it to not cook itself.

It’ll work, don’t get me wrong, but it’ll get damned hot. The LED, that is, not the case. And that’s the problem.