  The study of stellar-remnant black holes (BH) in dense stellar clusters is
now in the spotlight, especially due to their intrinsic ability to form binary
black holes (BBH) through dynamical encounters, that potentially coalesce via
gravitational-wave (GW) radiation. In this work, which is a continuation of a
recent study (Paper I), additional models of compact stellar clusters with
initial masses $\lesssim10^5M_\odot$ and also those with small fractions of
primordial binaries ($\lesssim10$%) are evolved for long term, applying the
direct N-body approach, assuming state-of-the-art stellar-wind and
remnant-formation prescriptions. That way, a substantially broader range of
computed models than that in Paper I is achieved. As in Paper I, the
general-relativistic BBH mergers continue to be mostly mediated by triples that
are bound to the clusters rather than happen among the ejected BBHs. In fact,
the number of such in situ BBH mergers, per cluster, tend to increase
significantly with the introduction of a small population of primordial
binaries. Despite the presence of massive primordial binaries, the merging
BBHs, especially the in situ ones, are found to be exclusively dynamically
assembled and hence would be spin-orbit misaligned. The BBHs typically traverse
through both the LISA's and the LIGO's detection bands, being audible to both
instruments. The "dynamical heating" of the BHs keeps the
Electron-Capture-Supernova (ECS) neutron stars (NS) from effectively mass
segregating and participating in exchange interactions; the dynamically-active
BHs would also exchange into any NS binary within $\lesssim1$ Gyr. Such young
massive and open clusters have the potential to contribute to the dynamical BBH
merger detection rate to a similar extent as their more massive
globular-cluster counterparts.
