Can I have my code and live view on separate screens? (macOS)

in fact design view helps a lot to quickly select part of document and directly acces to its code

node watch command automaticaly reload all the browsers connected to the node server as soon a specific action is done... it helps to avoid hitting many times F5 on each browsers, tablets, smartphones connected

My browser is open at all times which is  more reliable for previewing than either Live or Design in Dreamweaver.  Hit F5 to refresh browser.

although as @Ben107584 M indicates, I also using on the top screens a real time rendering (thanks to Node) on various versions of browsers... and this that the modifications are carried out within the display document (I prefer display view than live view in DW), or from the inspector of code, or Sublime text or any other editors

As you can see on the small screenshot, on the left screen the unlocked live view document hovers over a browser, on the central screen DW itselft and on the right screen the code inspector window hovers over a third program.

Solely within DW itself, not possible as far as I know. But if you have a browser open in your second screen with the testing server you should be able to work in code in DW and see the results in the other screen.

depending on your flow, and your organisation, you can still use the "code inspector" window, using F10 shortcut, or by the menu Windows > Code Inspector