  In the indicated preceding preprint (I), we reported the results of, in
particular interest here, certain three-parameter qubit-ququart ($2 \times 4$)
and two-ququart ($4 \times 4$) analyses. In them, we relied upon entanglement
constraints given by Li and Qiao. However, further studies of ours conclusively
show--using the well-known necessary and sufficient conditions for
positive-semidefiniteness that all leading minors (of separable components, in
this context) be nonnegative--that certain of the constraints given are flawed
and need to be replaced (by weaker ones). Doing so, leads to a new set of
results, somewhat qualitatively different and, in certain respects, simpler in
nature. For example, bound-entanglement probabilities of $\frac{2}{3}
\left(\sqrt{2}-1\right) \approx 0.276142$, $\frac{1}{4} \left(3-2 \log
^2(2)-\log (4)\right) \approx 0.1632$, $\frac{1}{2}-\frac{2}{3 \pi ^2} \approx
0.432453$ and $\frac{1}{6}$, are reported for various implementations of
constraints. We also adopt the Li-Qiao three-parameter framework to a
two-parameter one, with interesting visual results.
