Ray,
I don't think it is a big issue, as that asset is available in TRS2006 and TS2009, but not in the TC series as far as I know.
The problem is that even though people have bought the older versions, they don't always have them installed as they are using TC3 for instance, and don't have ready access to the built-ins.
As for Gresley bogeys, Andi06 has made some Gresley coaches with proper bogies including articulated ones. His site is here:
http://www.ajsmith.nildram.co.uk/trs/stock08.shtml
regards
stovepipe