Updates

Hi,
I assume that yes, your changes will be overwritten in case a new version is installed/updated.
You can block auto-update, although I would not do it myself – security is important. You might want to consider creating a different plugin that you maintain yourself.
I’m considering adding a feature (wordpress filter hook) where the final filename of the attachment can be modified by other plugins/themes – that would render your current plugin changes redundant.

Hi,
Plugin was updated to 1.2.0
File path and name are sent to your code, by means of filters and you can change it. Filter in question is: nmr_create_attachment_file_name
Do something along the lines (not tested):

// The filter callback function.
function example_callback( $file_name ) {
    // (maybe) modify $file_name.
    return $file_name;
}
add_filter( 'nmr_create_attachment_file_name', 'example_callback', 10, 1 );