Doesn't that have as much to do with battery life and software engineering effort than anything? Those sensors could already log data in much more detail by streaming into an off-the-shelf compressor like xz, but they don't because good compression inherently requires a lot of computation/battery-life and adds complexity compared to naive methods. There don't seem to be many use-cases where people having already plugged in zpaq but that just isn't enough and they need even better compression.