If it is listed in mdimport -e it can run with mdimport -m -y LOWERCASECONTENTTYPE -u PATHTOAFILE however the attributes aren't actually added to Spotlight's database. And even if the Spotlight extension is enabled in Settings->LoginItems->Spotlight Extensions, Spotlight will never actually run the extension itself. And if in the extension code you attempt to open the file with a try, it throws a permission exception so you wouldn't even be able to compute attributes anyway.
Topic:
App & System Services
SubTopic:
General
Tags: