This debate has been dragging on for years, much as it did for FDM/FOQA and CVR. The only certainty is that there will always be diametrically opposed views - some of which are entrenched - and that nobody will be happy with the outcome.
The (Annex 13) state investigation authorities want to see imagery, because it might provide some answers that would not otherwise be available. The pilot unions will always be opposed, in case the imagery is used by management for purposes other than safety. The answer to this is to make it unlawful to use imagery for anything other than an Annex 13 investigation.
The central question remains: what do you stand to lose by using imagery? The gains might not be present in every investigation, but that is true of FDR data right now. And if there are ambiguities, the investigators will deal with them in the same way they deal with any other ambiguous data.