SmarterWX does not limit the size of the geographic features that you can load.
However, we recommend that you avoid loading features that are very large or contain very large numbers of vertices. This will slow down your viewing experience on the SmarterWX map due to the volume of data to be loaded into the browser.
You may wish to break up large shapes into a series of smaller projects or exclusion zones.
Note that SmarterWX applies some basic simplification to the data you load to remove polygon vertices closer than 1m apart. Given the purpose of SmarterWX, any detail more accurate than 1m is redundant.
As a general rule we would recommend no more than 1000 vertices on a single shape and for a single shape to be no larger than a typical metropolitan local government area.