I started asking my boss to commit me to 6 months on a new stack if that's what they really needed me to do, making the argument that it takes at least a month

I started asking my boss to commit me to 6 months on a new stack if that's what they really needed me to do, making the argument that it takes at least a month to really become productive and several more to internalize the concepts. He understood and agreed that the constant context switching didn't make much sense because it slowed us down, but he couldn't make any promises. Things didn't change and I left a few months later when I got a better offer.