Hmm, maybe it was idle and not away that I was seeing in the nicklist. I did not even think of that.
Anyhow, it is nonsense that this will be a burden in the IRC servers or affect the performance or the IRC client. Many people use the IRC client and it would have been a known issue if it affected server performance and on the client side. I have tried these clients and the have these features and I know that it does not affect their performance, So I don't know what people are basing that assumption on.
Thanks for the feedback.