"He who marches out of step hears another drum." ~ Ken Kesey
Just because something will cure at 250* does not mean it has any bleed blocking properties.Traditional low cure formulas will start to "flash" or cross link at room temps. This specifically, is what he is referring to above.We have also seen this lately with other "low Cure" ink companies out there. Give the ink a few months and it looks like its turning into a door stop.
Yes it would need to have bleed blocking ability. If it did not, all you would achieve by the 250F cure would be delaying the dye migration until it eventually worked its way through to the top of the ink film over a few weeks time, or when your customer throws the print in a hot clothes dryer like I do when I do laundry.