It also (the forum), seems to be missing a subscribe to thread. When you come across an interesting thread, but the only way seems to be to put a post in it (to subscribe to it).
If the thread is something, that a person lacks any knowledge in, e.g. SPAM BOT gibberish (or whatever it is, possibly human?), creating a significantly nonsense thread, with very silly nonsensical questions (there is, arguably a current thread, similar to that, about storing electrolytic capacitors). It would be nice to be able to subscribe to it, without being forced to post in the crazy thread.
But also, being able to UNSUBSCRIBE from such threads, would also be very useful.
I suppose it is limits of the forum software system and its capabilities.