They certainly know about it, because its been brought up enough on the UKTS forum. There is also the issue about the relative lack of acceleration which other HST drivers have brought up (I wonder if the other powercar is actually dead?) and the lack of a graduated brake. Fortunately the latter is fixed by a mod on the forum, but you would hope they would look into it by now.
In fairness they are putting all their resources into putting in new steam locomotives, which is where the money probably is, and there appears to be some new effort towards scenario building tools (which are clearly needed). It will probably get done, but goodness knows when.
I idly wonder if this might end up at the front of the queue when the Blue Pullman comes out. I dont know if RS.com have any input into that development?