Hello Richard,
I fundamentally agree with the rest of the people on the site that there is little on scaffolding even in the Construction Certificate. (Two of my lads have recently done the course).
The NEBOSH route is a generic one that provides a "little of everything". My advice to specialise would be to then look at CISRS Scaffold Inspection courses to enhance your scaffolding competence.
Hope this helps,
Rick Statham
Joint MD
Safety & Access Ltd