ok I re-revisited a scene I created last year, changed pov etc hit render and five+ hours later it was a disaster...some extreme displacement artifacts/errors....I re examined the node network and tidied it up, fixing extremes of smallest scales and displacement amplitudes of power fractals etc, and deleted an extraneous compute normal(

) I re-rendered, this time it came out as I was expecting but rendered in under half the time....a few lessons learnt over a year!
here are the results of the last few renders....
no wp btw, just jpegged....