Sorry for lack of clarity.
I was talking about being already on https://kagi.com/maps
Bangs are not working there.
And now when I check it there is link to google maps visible on desktop but hidden on mobile (you need to click on the bottom popup to show it), so my fault for not finding it there. I would just prefer if clicking it could replace kagi maps page instead opening new page.
This is view on Firefox on Android, there are some css problems (like Relevance and Rating partially cut):