i have to admit i can't comment on the chunk technique (most of the time using win and trying to avoid DP support) - but i think i get the priciple ...
basically sample data which is not already in memory needs to be loaded.
say if a chunk contains only solo strings and you are loading now a chunk for chamber you need to wait.
other scenario: you have a larger preset loaded across several instruments and are now opening a chunk which contains patches (or matrices) which are not already referred referenced, so you need to wait until the missing patches are loaded
hope you can see it highly depends on the situation and what type of chunks should be loaded ...
christian
and remember: only a CRAY can run an endless loop in just three seconds.