This was within Kant's expectations.
The posthouse was the only way to pass through the Rocky Pass and the Oasis Lookout.
As long as there were people who wanted to test Kant and came to the depths of the desert disguised as trade caravans, they would pass by this flat sand plain. The posthouse that was being built in the middle of the sand plain could be said to be extremely conspicuous.
No one would give up the idea of testing the posthouse.
Moreover, in the area around the possible routes, 40 desert bandits would carry out continuous patrols.