A node has 8 slots,

Make a scenario: there are 3 static mat's in the node.

At slots 2, 5 and 7.

That leaves 1, 3, 4, 6 and 8 open for a treasure Map.

A Bot could script to hit all those opened nodes and there is no penalty other than time the bot has plenty of. Then allowing the script to hit the favored node. Usually a shard.

So rather than have empty nodes, put worthless gravel or worthless mulch in the empty nodes. Every so often they will be replaced with the map.

This way if a Bot tries to target static empty slots in their script they will fill up on worthless gravel and mulch and pretty much bork their bot.