Uh? What's that got to do with any of this?

The default N900 is like an oven without a dial, just a big "auto-cook" button. The K## packages provide lots of thin metal cylinders you can turn to change the settings, but most can't grip them well enough to use them directly. The settings package is "the big plastic knob" on the front that makes it easier to use. But if you turn the oven up to twice it's rated value and it catches on fire, it's not the plastic knobs fault.

Some devices simply can't operate at faster speeds. It has nothing to do with the tools that configure the system. It's a hardware limitation. Nokia/TI tested these to work up to 600Mhz. Some reboot at 605Mhz, some reboot at 1200Mhz. If your device explodes randomly going over 850Mhz, then don't set it above that. Done.