Client sided is possible, the matter is finding the bricks (which you can loop through the serverConnection group).
Granted it'll be a bit slower.
However, really the only issue with the idea is how to generate the map.
As I've suggested, there is the idea of swatches but that's slow as hell.
I cannot think of any other method other than that, without requiring something external.
Then there's radar. It's been done, and taken down for good reason. It's so overpowered and abusable.
With a server/client script, it wouldn't be that abusable.
And if the host wishes it, he could disable the radar.