I thought the VIEW "Layout Parameters" setting "Word wrap" value is not persistent and does not seem to be saved to the DIAdem desktop "Desktop.DDD" file. I think it should either be persistent or added to the saved parameters for the Desktop.DDD file.
The workaround is adding "View.Settings.UseMultilineLegend = 1" to some startup script which is fine, but I'd prefer it to be persistent upon changing it.
Long live DIAdem Word Wrap Legends!