Comment by cromka
14 hours ago
The activity generator may be a tool on your PC which is well aware of the hidden partition's presence. All it has to do is changing partition size before writing anything, then restoring it. It may also generate using your real data, which you explicitly ack. Some safe communication with your grandma and mother, some messages from your employer, banks, other recent 2FA codes. You white flag contact names and it does the job for you.
The problem with pre-generated activity is that it must cut off at (or shortly in the future of) generation time, to be plausible.
Otherwise that activity would be suspicious due to either a lack of recent records, or of presumably implausible future ones.
Generating data in advance and applying or updating timestamps later, on an ongoing basis, or when a duress code is entered is a possible way of mitigating this. There's the question of how convincing such data would have to be. White-flagging and generating (or appropriating from public sources, e.g., business or institutional entities) contacts for this might be a part of it. This is similar to but not entirely the same as data fuzzing, which is generally seen as applying to a primary data trail.