This is quite a common result for exploration drilling programs...

This is quite a common result for exploration drilling programs seeing many points return 0% of a target resource. It sets a boundary of where the deposit actually lies after first establishing the businesses "estimate" of where it lies. This data then allows the business to zero in on where they are going to focus the advanced mining programs and avoid the areas that you have mentioned returning low FC%s. There is obviously forming a pattern in the middle of Mangabe (save for the dead centre which they have already established doesn't contain graphite for whatever reason and auger drilling has confirmed), and just to the east of Mahela. Everywhere else they won't bother with.

These are fairly expected intersections for this deposit with the majority of returns falling around that mid 4% range. I haven't gone back to review the previous auger results but 8% would be one of the higher returns so don't use that as an indication, it's more likely a tiny patch that has a higher concentration. 4% (and maybe up to 5%) will be the weighted average of the next JORC (so nothing ground breaking) but it's about increasing the Indicated & Measured resources portions to achieve the label of medium scale mining venture and opening up a raft of new investment opportunities.