Unfortunately useless: when loading a new page or refreshing a page, the extension gets unloaded and disappears preventing the debugging from the moment a new page is being loaded or refreshed.
Only works once a page has been loaded and until that same page is unloaded. So for me who wants to debug pages from the moment they start being loaded this extension is unfortunately useless.

works well.

on mobile: while on the site to debug, click on the hamburger menu, then the extension, and a very transparent gear icon will appear in the left right corner of the screen. hold it to place it somewhere else. tap it to open the eruda console.

inspecting styles:
elements tab, then tap the inspect icon and the console will hide until you clicked on the element you want to select.

does not show on some pages, like grok.com (no gear icon shown). maybe because the page elements are in a higher layer? but not a fault of the extension.

thank you, Mr developer.