Could you please add a history button to the sidebar? It could be really similar to the bookmarks button, but it displays the browser history.
I know I’m a little late, but you can use split screen for this. You can either right-click an already open history tab and click ‘New split view with current tab’ or right-click the current tab, click ‘Add tab to new split view’, then open history in the other pane.
It’s better than two windows at least.