It is not exactly true that you can’t see Weaver Xtreme Per Page options for an Elementor page. You just can’t see them while editing using the full Elementor Editor.
There are a couple ways of getting to the Weaver Xtreme options.
Start with viewing the page while viewing it on the normal site view while logged in as an Admin/Editor. To see Weaver options, Click the plain “Edit” option at the bottom of the page. This will open a view of the page that has the content replaced with an “Edit with Elementor” button. At this point, you can access Weaver Per Page options.
If you are currently editing with the full Elementor “customizer style” editor, you can either update and exit and get back to case 1, or you can click the “hamburger” menu in the top left, and click the “view page” option, which gets you back to the starting point for case 1.
But, there is no way to show Weaver Per Page options from the actual full Elementor editor. This may also be true for other plugins have per page options. You have to get back to the core WP editor to see these types of options.
I doubt that we will ever have the resources to add Weaver Per Page options to the Elementor customizer interface. I would guess that it would take several months of development just for that, and we simply do not have those resources.
There is a tiny “bug” when viewing a page in the full Elementor editor – the two “Edit” links still show at the bottom, but don’t actually do anything. I don’t know if this is an easily fixable problem – just possibley confusing until you realize they don’t work.