I'm sure you're right but I just haven't got that far. Whatever I do with applying FX (such as the Zoom function) the FX instantly applies to that entire track rather than to just the portion I want affected.
Very frustrating at first, but it has led me to be a bit more creative. I now zoom in on the guitarist for the entire song and save that track as GitKam, repeat for each of BassKam and DrumKam, and then I can crossfade between the five cameras quite freely.
The tricky bit is having to decide in advance which shots I want from each of the virtual cameras, so that I can discard the unwanted bits before I load everything up for the main edit. That way, instead of loading up 5 x 1.6Gb, I can load up 2 x 1.6Gb and perhaps 3 x 500Mb.