Google finally added an preference setting that provides a reasonably sized compose window, but (presumably) in keeping with their new interface guidelines, it'

Google finally added an preference setting that provides a reasonably sized compose window, but (presumably) in keeping with their new interface guidelines, it's well hidden to prevent accidental discovery. To change it, you need to open a compose window and click on the "down arrow" in the lower right corner. You can then choose the option "Default to full screen". It still pretends to be a pop-up window, but it's large enough for real use. Arguably, this is a reasonable place to put this setting: it affects only the compose window, so the setting is only accessible from the compose window. But personally I never would have found it without searching the web for a solution.