my controller or hand can collide with a square that is roughly the size of city hall, perhaps a bit larger
i can press any button (or pinch) while colliding, hold it down (or keep pinching), and move the town hall and also the entire grid of my city (this could be a geometry on the same as the anchor city-container entity)
it will also attempt to replace the anchor, ideally a persistent spatial anchor
bonus: add in-vr messages to notify component and use it to confirm anchor updates (or failures) for debugging
as a user I can change the anchor location
with vr or hand controls: