"Meso-mining" means reducing always the entities of the world to their supposed finished states as frozen objects. What's fully formed or fully individuated is always primary for the meso-miner.
If meso-mining is true, essential natures of whatever is ("objects") are already realized in the sense that being determinate they are always already actual and hence always already possess an identity - at least in the following manners a.) they suffer the principle of individuation (and thus suffer the principle of identity); b.) they are modally determinate (actual and essential rather than virtual or possible and vague).
Even if subsisting virtually (or ideally, or non-materially, or "essentially" - however the Swedenborgian mystic who is using intuition and allure - rhetorical flourish though, mostly - to discuss these essential natures, bound up as they are within the secret lives hidden inside of doorknobs or watermelons or whatever item the meso-miner is attempting to convince us is ultimately relevant - there is a very simple category mistake being made between an essential nature itself and the power for or capacity to achieve such a nature. The capacity (better read, power) for particularization itself is not any sort of reality which is a fully determinate reality (virtual, spiritual, actual, material, or otherwise). In other words, the capacity for further particularization does not consist of fully determinate correlated particulars - particular essences correlated to any identity behind names, nouns, or variables (as for the meso-miner for whatever name there is there is an essential nature "out there" already). Thus the realist moment of such a view topples over into a full-blown nominalism for the meso-miner.
Here the meso-miner assumes that not "above" or "below" but beyond what is real, there are essential, eternal natures for whatever is, and such is true for each unique specific individual that exists: all is frozen and fully determinate. (As an aside, we immediately see problems for time or temporality; for universals; for change; for creativity.)
And so, given this nominalism, the claims of the meso-miner must be patently false - especially in a continually becoming universe where only contingency itself (i.e. "becoming") is the ultimate, necessary, creative principle.
Take the two following theses of the meso-miner:
1. Objects (i.e. particulars, things, discreta, that which is independent of relations or change or that which fully exhausts relations or change) are absolutely independent of subjects.
2. Subjects are objects.
If the above, even if essential natures are just "assumed" - just taken to be true independent of contingency, change, temporality, creativity, the capacity for particularization - given the reality of contingency, change, temporality, creativity, etc. then we can never truly claim what these essential natures are. This is to say that we have no criteria by which to judge what is subjected to a. and b. above (a process of individuation and whatever form of being modally determinate) if other modal categories or principles are in play, even if secondarily.
There is one other very significant problem for the meso-miner: that of reason. Oh boy, does reason forever draw the ire of the meso-miner.
Whatever secret nature or essential transcendent essence hiding inside of the doorknob or watermelon, the meso-miner needs to keep that essence "always already" a secret and hidden from rational exploration, yet at the same time, attempt to maintain that such an unknown essence correlates conclusively to a name so as to be that thing and not some other. Yet if correlating to a name and always already being determinate, reason or rationality - not even necessarily as employed by the human, for rationality in the sense we are discussing could be "extra-human" or "trans-human" - would be able to, itself and alone, fully expose these singular natures if each nature belongs to the same fact of reality as reason (that is, if essence and rationality are contiguous within the world, if each belongs to the same reality in which there is no fundamental ontological divide so that whatever principle of explanation applies it does not apply differently in each and every case).
But for the meso-miner this is impossible given both a. and b. above and hence it leads to a fundamental contradiction in their philosophy.
Therefore, the objectual reductionism of meso-mining is patently false. Or, we can say, it is "refuted."
(If interested, I somewhat discussed this some time ago, HERE.)