Greetings from Syncfusion!
We have the support to load the shape file as stream. Hence, you can achieve your requirement by converting the accessed shape file (from your device location) to stream and load to maps using ReadAsStream() method.
Please refer the below code snippet for loading shape files as stream.
// Load Shape file only
// Load Shape file and dbf file
We have prepared the sample to load the shape file from the application. Please find the sample from the following location.
Note: We need to convert the loaded shape file into stream and then load stream into maps.