Actually the claimants use it intermittently while the UC office staff use it for much of their working day. I don't know for sure, but it's a pretty likely that it's actually quite a bit harder on them.
So cases don't get worked and UC doesn't get paid. In other words: working as intended.
It's better than it used to be. Still, a way off from what it needs to be.
The first version was on Microsoft Dynamics (yes a CRM...) for whatever reason iirc.