The detail I find annoying about the serial monitor window is how it interacts with the upload process.
While the upload is in progress, the “open serial monitor” button is a no-op.
You have to watch the status bar to detect when the upload is done, then re-open the serial monitor window. That, in turn, will reset the (already) running program on the board, causing more delay. Some of the first bytes sent by arduino are also lost. So to catch them you have to hit the reset button on the board while the serial monitor window is open.
I’d like to have an option to tell the arduino IDE to open the serial monitor right after the upload and avoid the double-reset of the board.
My vote goes to a second “open serial monitor” button, near the current one, which would cause the serial monitor to open automatically after the upload. As an alternative, a togglable menu option could also work IMHO (something like Tools=> Open SM after upload).
My 2 cents…