This implementation already exists, but only for ITSM.
I believe that a similar feature would be useful for the DWP/DWPA platform as well.
The main idea of the above article is that the user is prompted with a pop-up message which notifies him that the session will become invalid in 5 minutes. More details on the mentioned article.
Special thanks to Stefan Dragomir, for the original idea for SmartIT. I was too lazy to think up my own text. Your explanation is too good.
There is no reason to treat these two products differently. The users partly use both and expect a homogeneous behaviour.