Miaphysitism is very similar to the Hypostatic Union.
Miaphysitism (sometimes called henophysitism) is the Christology of
the Oriental Orthodox Churches. Miaphysitism holds that in the one
person of Jesus Christ, Divinity and Humanity are united in one
"nature" ("physis"), the two being united without separation,
without confusion, and without alteration. (Source)
The term miaphysic is best understood as ''one united nature'' i.e. two natures united in Jesus Christ and thus, it is different from monophysitism (''one nature'' not two natures in Jesus Christ).
Contrariwise, the Chalcedonians saw the Oriental Orthodox as tending
towards Eutychian Monophysitism. However, the Oriental Orthodox
persistently specified that they have never believed in the doctrines
of Eutyches, that they have always affirmed that Christ's humanity is
consubstantial with our own, and they thus prefer the term Miaphysite
to be referred to as, a reference to Cyrillian Christology, which used
the phrase "μία φύσις τοῦ θεοῦ λόγου σεσαρκωμένη", "mía phýsis toû
theoû lógou sesarkōménē". The term miaphysic means one united
nature as opposed to one singular nature (monophysites). Thus the
Miaphysite position maintains that although the nature of Christ is
from two, it may only be referred to as one in its incarnate state
because the natures always act in unity.
In recent times,leaders from the Eastern Orthodox and Oriental
Orthodox churches have signed joint statements in an attempt to work
towards reunification. Likewise the leaders of the Assyrian Church of
the East, which venerates Nestorius and Theodore, have in recent times
signed a joint agreement with leaders of the Roman Catholic Church
acknowledging that their historical differences were over terminology rather than the actual intended meaning.(Source)
In my research, myaphisitism is indeed compatible with the dyothelitism of Chalcedon.
The identity of the original human being was known by name. God named
the first human beings , the male and female, with a singular name
'Adam'. Scholars say that the name 'Adam' applied to Eve in Genesis
5:2 was a designation of her equality with the male in human nature as
stated in Genesis 2:23 where the male said that the female was the
flesh of his flesh and the bones of his bones. In this case, God was
treating human beings, male and female, as one.
The union of the divine nature and human nature in a singularly named person called 'Jesus' was similar to the spirit being united with flesh
which was called singularly as soul (cf. Genesis 2:7).
Consciousness existed in the mind. In Jesus, the human mind and the
divine mind were one i.e. in unity/united. This meant that in Him
was united minds or one consciousness. This one consciousness had two
distinct divisions in which similar but not identical to the Perichoresis of the Trinity, the divine part had full access to the human part whilst the human part had varying access to the divine part -- from limited access
during his ministry before the crucifixion to full access post-Easter.
If the divine mind and human mind were two consciousness in Jesus, it
would mean two separate persons (Nestorianism) which would be akin to
Multiple Personality Disorder (MPD) wherein there existed ''split
identities'' (www.webmd.com) in which there was multiple names for
each person existing in one body. This was not the case in Jesus
Christ. (Jesus Christ: one person with two minds based on biblical
Anthropology and the Perichoresis of the Trinity, R. Brown, 2020)
