So MSDN features a 'How to: Set Up Service Item Components from BOMs'
https://msdn.microsoft.com/library/hh177556(v=nav.71).aspx
However, there appears to be no native functionality to bring through the 'components list' for a BoM which was customized from the sales order line.
Has anyone conceived a workaround for this? Without having to manually recreate every BoM in the service item?