estimating into a small volume using a separate, larger domain defining samples to be used

The RBF numeric interpolants allow one to estimate into one domain using samples from a different domain.  I would like to do the same using the regular estimators.  For example, at an open pit porphyry copper deposit I have a 50x50x40ft block model for the entire orebody, but I wish to estimate quickly into small monthly asbuilts as part of a reconciliation process.  I built an octree block model using the production assays (blastholes) with the asbuilts used as a trigger to get precise tonnages for the asbuilts.  The problem is that the estimators code the entire block model (time consuming) when it seems the estimations could be limited to only those small monthly asbuilt volumes.

A separate observation is that if the geologic model used for the trigger is smaller than the octree model the sub-blocking will use the geologic model's extent as well as any geologic contacts.  It seems using the extents as a trigger needlessly adds blocks.  (I changed the block model to match the geologic model extents to avoid this, but wonder if a change in programming would be useful.)