Ice particle icing in engines and restart alt.
PJ2: My impression of the ice particle icing paper was that engines could not be restarted usually above 10k feet because of the time required for the ice blockages to clear. Note in the paper it mentions that engines that were not shut down recovered function at about the same altitude. So while I don't doubt that A330 engines could behave differently, I don't think that it necessarily follows that they would provide power at a much higher altitude.