It would greatly speed up filing if there was some way of ticking all the emails that you wanted to be filed in the same place, then hit the file button. Is this possible ?
The subject tag does not always need to be changed so this step could be ommitted for bulk filing. When the subject tag does need to be changed those e-mails can be filed individually as normal.
Alternatively the subject tag could be applied to all selected e-mails allowing e-mails related to the same subject to be filed in bulk saving time and money.