The RR BR710 engine on GLEX, G500/550 and B717 have had several ice crystal incidents. I cannot say for the B717, but some have occurred above FL410. The engine rolls back while under FADEC EPR control, presumably ice crystal icing on the EPR probe. The advised solution is to switch to N1 control.
When I was at Eastern we had a B727 at FL330 enter clouds when the TAT indicated no potential for icing and promptly all three rolled back to a near-idle condition. They managed to restart them, but the company advised crews operating in tropical conditions to not hesitate to turn on engine anti-icing even if not strictly called for.
While I understand Rainboe's point of view, we should be open to the fact that the atmosphere holds a lot of surprises that, perhaps, only the dead know for sure. Just because the information is in technical publications and hasn't made it into flight publications, isn't to dismiss it. OTOH, we shouldn't be making up procedures in the cockpit, but where is the harm in using engine anti-icing when under these conditions?
GF