I know one example does not a theory make, but I was recently listening to the latest Wessex Archaeology podcast. In it they were talking about a barrow they had recently excavated (I forget where the site is). The ditch was cut into the chalk (so that narrows its location down) and its bottom was flat and polished smooth. To go to that amount of effort must mean the ditch (at least in this instance) was important.

Another example was discovered during road building works in Finglas, north Dublin. There the ditch of a small henge was lined with animal bones. The circumference seemed to have been divided into sections with each arc carefully lined by a different kind of bone, so one section had jaw bones, another had leg bones etc.

However, I have often wondered why if the ditch at Avebury and other places was so important why they left it full of old antler picks.