Tonight's update focuses on this very topic!

Spectators are not ignored, rather they are listed as a separate number (if the user opts in).

Holding down tab does do something, but something that cooba suggested in 2007 instead.

Currently bots are recognized by name, not by a special packet like in the original suggestion. The server with the most bots is still running JJ2+ v5.12; there's just no way to get that server to run any new code to read such packets. If anyone tries to make a bot whose name doesn't begin with "Bot" or "AI " then we'll all just have to peer pressure them into conforming. We also hope to add proper bot support to JJ2+ eventually, which will also use the "Bot" name scheme.