Interesting! I didn’t know that less chests spawn close you the point you enter the map.
I don't know the exact distance but from what I experienced in pongmei from starting at boreas it is about three to four compass ranges until the first possible chest spawn. Smaller maps may have a closer distance to the first possible chest. Even tho this game is over 16 years old, we still don't know everything. Just explore some threads here.
For example:
Thread
The number of possible chest spawns per map! A constructive discussion.
Dear community,
first of all, english is not my native language so excuse the mistakes in the following text.
Today, someone in my alliance chat stated, that he had zero chest spawns while vanquishing Maishang Hills. I was answering in alliance chat that this is just impossbile. A map of this size has to have chests. After some minutes of discussion we both were still defending our statements. I am sure, maps of this size have chests. Especially Maishang Hills has some nice corners with pop-up…
first of all, english is not my native language so excuse the mistakes in the following text.
Today, someone in my alliance chat stated, that he had zero chest spawns while vanquishing Maishang Hills. I was answering in alliance chat that this is just impossbile. A map of this size has to have chests. After some minutes of discussion we both were still defending our statements. I am sure, maps of this size have chests. Especially Maishang Hills has some nice corners with pop-up…

Jodel_GW