How can I switch on the chat windows separately? I could swear that this possibility existed in an old version!
If I read, however, here, some say that there is not this. Can somebody say me whether was there the function or gives to have chat window separately and not in Tabs?
There was never such option in Spark. There is an open feature request and at some point a patch was in the works, but then that person left, so his work is unfinished. https://issues.igniterealtime.org/browse/SPARK-893 There are currently no active Spark developers to add this.