I haven't had any problem with my hacked 3303x, besides one time I damaged the select-able 5V rail. But I've hardly stressed the PSU, most stuff I've powered was pretty low power, and for fairly short duration tests/etc.
But my cables and connectors aren't the best, and can sometimes drop a few mV or more, I know that's usually fine. But has anyone looked at the circuits in detail, and thought about adding voltage sensing out at the DUT ?
I'm not sure what would be involved with that, maybe too much stuff would have to be changed.
I only have one, brandname bench PSU (I made one too) so I'm in no rush to open it back up, but I did want to mod the 3rd rail a bit, I think by adding some warning LED's or some protection that was not added, or something, I can't remember, I mapped some of the circuit when I fixed it ages ago.