File transfer is already complicated and takes some time to negotiate and now one wants to do this not with one but with ten people?
Within a company one could write a simple SparkPlug which uses a SMB/FTP/HTTP upload and sends a link into the MUC. The receiving clients with this SparkPlug could detect the link and filter/convert it to “incoming file” as they know the server.
The SparkPlug may also support file encryption, so one could send the key with the link.
For me, not so much sending to more then one in the room, just able to right click on the user in a room and send. Rather then opening up a private chat with them.