MODU Sea time - thought we settled this

Hmmm… NMC denied my STCW 2010 Qualified Assessor endorsement because the sea time I submitted was on drillships. They don’t say how much time you need. I suppose I’ll resubmit after I figure out how many days of moving over ground I have and not just through the water. Anyone else have this problem? I thought it’s been a long established precedent vessels on DP are underway.
[I]
“The time submitted aboard MODU’s or Drill Ships does not distinguish between time on station or time underway that is reasonably equivalent to that on conventional vessels.”[/I]

Obviously as an assessor you wouldn’t sign off on something you can’t witness. But why make a blanket statement? How do all these school instructors with no time at all get the approval?