I can just select the element with the extension but it only grabs the canvas and not the style. The canvas is self modulating / gets replaced meaning it just opens a new ad after a while, or after a refresh. However on this particular site most of the style from the start is the same only the end changes, meaning you can just block the style with "style*" and enter the start of the style in order to block it.
site.com##div[style*="display: block; position: fixed; z-index: 2147483647;"] should block every style starting with "display: block; position: fixed; z-index: 2147483647;". however nothing happens.
Im on a quest trying to block those pesky self evolving advertisements that are tweakbox appvalley https://vlc.onl/
baked into sites. Some (all? unless the script handles more then one thing) are running with scripts that can be blocked, however iv not found a extension that allows block per content, they just lump every type by url.