@Mar ****
In the specific case of the DTV, as long as you don't need to use immigration for anything and assuming you always do a border run and don't extend in country, I don't see how this can be enforced.
Andi mentioned through the new ETA system (although that's only for visa exempt travelers) but it supposedly comes with a comprehensive new surveillance apparatus
That's a possible way, but if it applies, it hasn't been implemented yet.
What I'm saying is that up until now, enforcement of the 90 day report has been done purely by your immigration office and that pertains to those on extensions of stay.
This visa will be an interesting case study to see whether it changes but I suspect until a new enforcement system is in place, in practice anyway, nothing will happen because immigration officers at the border aren't interested in TM30s or TM47s.