OK, Good question! Your question is answerable, settle-able.

1. Let me correct: you have already found how to find all the data type (...)... castings(implicit type conversions) with MS VS extension, Are you sure you wanna export'em to an .xml file, will .csv or .txt file do?

You have asked lastly within this thread:

Is there any method to find all the locations of implicit type conversions in C# code?

All the locations of implicit type conversions in code file are already found with that Resharper extension, aren't they?

You may need the extension output to .xml file saving functionality, Do you have the source codes of the Resharper extension, if yes to add the function bool save_to_file(stringlike_datatype button_find_results) {...} to the resharper extension source code.

Have you found already another addon with such functionality already implemented(realized)?