If there are no browser windows open, opening a new window with multiple tabs will have a delay. The window will open immediately but there will be a 5-10 second delay before the subsequent tabs open. How do I circumvent this?

Edit: I realised that this was only a problem when I register a browser, e.g.

webbrowser.register('Thorium', None, webbrowser.Chrome(path))
Thorium = webbrowser.get('Thorium')

Thorium.open(";)
Thorium.open(";)

Therefore, my actual question is how do I avoid this behaviour when using a registered browser?