Extension to magnify spot on any webpage?

I frequently use map sites like MLRS & Google maps. The text on these maps is incredibly small. When I zoom in, the text stays the same tiny size so I need something to be able to zoom over the spot when I need to read a road/street/lake name, etc.

Afaik the extension Zoom+ only works for some websites, not all, for whatever reason, and the sites I use arn't on the list.