Ok, I read a bit, watched some videos, so I think I now understand what you mean. Still:
>all you need to do is compact incoming data to the local context you know.
Wouldn't that mean that if it comes from some other context, you first need to expand it, before compacting to your own context?
If the expansion can indeed use unbounded memory, that'd be a serious problem.
I think in such situation, comparing incoming context to a hardcoded URI would be the saner of two approaches.