[mkl]

You can have multiple keyboard layouts installed, and it takes a fraction of a second to switch with a shortcut key (on Windows it's Win-space). I have a Māori keyboard layout installed on my work computer, but I only switch into it to type words with macrons, then switch back (I use ` more often and don't like having to double-press it).

[lmm]

Sure, but even if I switched back and forth, the keys would be in the wrong place (because you can only have a qwerty layout with macrons, right?). Somehow the model is wrong compared to Linux where I can do compose to get a macron on any "underlying" layout.