Editing the crontab requires unpacking the Sony firmware update file, modifying a file, repacking it, then performing a USB update with that modified firmware.
The hack is to create an executable file in the /psp partition, then set the crontab to execute it after a certain amount of time. That hack would presumably interrupt the normal boot process and redirect the device to do something besides what it would normally do.
There are a couple of issues with that:
1) The firmware image is covered by copyright. Sony has not granted anyone the right to modify and redistribute a firmware image.
2) Many, if not most, current Sony dash users have already updated their devices to the latest version. Presumably there were other things that Sony did for that update besides disabling the cron hack.
3) Exactly what the device may be doing when the cron task fires may not be very predictable.
4) It's simply not necessary for what I'm trying to do.
As an individual, you probably wouldn't get any reaction from Sony if you choose to modify a copy of the firmware and use that yourself, but I'm not a lawyer, so this is just an uninformed opinion and should not be taken as legal advice.
Blue Octy, on the other hand, cannot and will not take the legal risk, since I would be doing mass distribution of this new software, as a company. I am not modifying any Sony intellectual property.