switching might behave different from (additional) loading - as long as patches are referenced they don't get unloaded.
to stay with the figurative explanation: closing a *chamber chunk* having chamber not referenced from other tracks will unload chamber data, now opening another *chamber chunk* will reload chamber data, just opening an additional *chamber chunk* will only load the missing patches, since a certain amount of chamber data is already referenced.
hth, christian
and remember: only a CRAY can run an endless loop in just three seconds.