Would be awesome to see the "Element Eraser" that was recently added to desktop make it's way onto mobile. I use it semi-regularly on desktop on on Mobile Safari through the AdGuard extension -- basically building something similar for mobile.
There's two main user interactions with this feature -- selecting an element and then the removal of existing ones. For Safari + AdGuard, the user flow for doing this: selecting the icon(s) to the left of the address -> AdGuard extension -> "Block Element" -> Element chooser (who's UI I wouldn't mind being copied for both desktop and mobile!)
As for removing an element, AdGuard makes you go to the AdGuard app to remove it.
That said, if I were the one to implement this in Orion Mobile, I would put the "Block Element" option below the "Reader Mode" option, and have removal go in the "Website Settings" menu.
Thoughts?
Cheers!