Drilling can only be done in the dry season. Apr/May-Oct/Nov so...

Drilling can only be done in the dry season. Apr/May-Oct/Nov so that certainly slows things down in terms infill drilling to get the resource to a level they can do the PFS/mine studies.
They had tested the geological model post scoping study mid 2017 (prior to that the resource could be described as average at best):http://www.aeonmetals.com.au/assets/uploads/2017/07/2017-Jul-28-Zambian-Copperbelt-Style-Geological-Model.pdf
Only way to speed it up would have been to add additional drill rigs In 2018 on which would have added more costs (more cap raised) or reduce exploration drilling along strike .
What has been a let down and delayed the process is the met testing - why did they not look at testing of multiple processing options earlier? The bio-leach process came late in the piece (which looks good so far in terms of costs/recoveries) - well after they pursued the leaching option with Outotec for 1 year +. Why not run the different options in parallel which would have saved significant amount of time and we would have likely had our PFS by now.