maxdisplayed for markers in scattermap

I'm often dealing with gps position logs and plotting them on maps to see where measurement targets have been moving.
These have loads of points, so for visual clarity I do not want markers on all points.
For normal xy scatter, there's marker-maxdisplayed , but there seems to be no analog for scattermap?

首先定位 scattermap 标记的实现，并将其与 issue 中链接的现有 scatter marker-maxdisplayed 参考进行比较。确定 scattermap 当前如何选择和渲染标记，然后验证所请求的限制能够适用于密集的 GPS 点数据，同时不改变其他标记的行为。当 scattermap 提供等效选项，且其行为由相关的 chart 测试覆盖时，即可视为完成。