  The $\mathfrak{osp}(2,N)$-BF formulation of dilaton supergravity in two
dimensions is considered. We introduce a consistent class of asymptotic
conditions preserved by the extended superreparametrization group of the
thermal circle at infinity. In the $N=1$ and $N=2$ cases the phase space
foliation in terms of orbits of the super-Virasoro group allows to formulate
suitable integrability conditions for the boundary terms that render the
variational principle well-defined. Once regularity conditions are imposed,
requiring trivial holonomy around the contractible cycle the asymptotic
symmetries are broken to some subsets of exact isometries. Different coadjoint
orbits of the asymptotic symmetry group yield different types of boundary
dynamics; we find that the action principle can be reduced to either the
extended super-Schwarzian theory, consistent with the dynamics of a
non-vanishing Casimir function, or to superparticle models, compatible with
bulk configurations whose Casimir is zero. These results are generalized to
$\mathcal{N} \geq 3$ by making use of boundary conditions consistent with the
loop group of OSp$(2,N)$. Appropriate integrability conditions permit to reduce
the dynamics of dilaton supergravity to a particle moving on the OSp$(2,N)$
group manifold. Generalizations of the boundary dynamics for $\mathcal{N}>2$
are obtained once bulk geometries are supplemented with super-AdS$_2$
asymptotics.
