My before and after mining test
all mining was done in a serpentis burrow, because you get a consistent volume of rock in every one, you enter.
previously you could expect about 2 orca full of ore out of a burrow. about 400,000m3 of rock.
with an exhumer with type 2 strip miner and type 2 simple B crystals, you only get 180,000m3 of rock.
I realise you would get more rock with a type2 A crystals.
what i found was that there are a number of small rocks, that when mined give you, no yield in your hold, it all goes to wastage. with theses rocks you just pass them by.
there are also small rocks that are between 1 and 2 cycles in size. with these, you can do a full cycle, and then start/stop every 1/4 cycle, to minimise wasting time on them
with the the type 2 A crystals, there was still a number of rocks that would only yield waste.
I did find that a serpentis refuge with rocks was way worse, as well over 3/4 of the rocks yield only waste. to type 2 A crystals.
my conclusion is that the rocks in combat anomalies never got buffed, like the belts. on the up side, it only took about a 1/3 of the time to clear the burrow of minable rocks.
ps.
i did not look at standard belts as there is no way of get a consistent amount of rock each day or time you enter a belt, compared to the combat anomalies.