Very good addon. The feature to show the port number in URL is very useful.

Would be great if there was an option to write the url after the title and not before...
You say in the preceding comment that is is not possible, but some other webextensions addon are doing it:
https://addons.mozilla.org/en-US/firefox/addon/custom-titlebar-text/
https://addons.mozilla.org/en-US/firefox/addon/hostname-in-title/
https://addons.mozilla.org/en-US/firefox/addon/url-in-title/

But for these extensions, if we drag & drop the Firefox url in Windows Explorer, the url is contained in the created shortcut filename, which is useless and very bad (filenames are too long). I don't know if this is the consequence.