You can also goto https://example.com/, bookmark the page (to the start page as a speed dial or to the bookmarks bar for example), goto the URL opera://bookmarks, edit the bookmark/speed dial, and change its URL to chrome-extension://pdcifnciicbfakdajkbbhphlabjminhg/sidebar.html and its name to "GX Control". Then, if it's a speed dial, you can change its thumbnail to a local pic of your choice.

Also, for now, you can goto the URL opera://settings/keyboardShortcuts and set a shortcut for the "show sidebar" command to toggle the sidebar. I like to use F4. Then, you can press it to show the sidebar, and click the GX Control panel., adjust the things you want, close the panel and press F4 again to hide the sidebar.

Also, for now, there might be some Chrome extension you can install that opens chrome-extension://pdcifnciicbfakdajkbbhphlabjminhg/sidebar.html in a new tab when you hit some keyboard shortcut. Where the shortcut works might be limited to regular web pages though, but...