Yes, the underlying engine of Picat is - a slightly altered- B-Prolog, which is available as the "bp" module, from which one can use many of traditional Prolog constructs, for example `bp.length/2` instead of Picat's `length/1` function. This can help when porting Prolog programs to Picat. In fact, quite a few Prolog programs can be run directly in Picat, perhaps with just some few adjustment.
I really like MiniZinc, especially that one can test a lot of different type of solvers for a problem.
But one of its drawbacks is its limitation of handling input and output (including preprocessing and postprocessing). In some cases - for example when the output is rather simple - I use for example Picat/Python to transform input to MiniZinc format (.dzn format or JSON) and then run MiniZinc.
But for more fancy output I tend to use Picat or Python + (OR-tools CP/SAT or CPMpy or minizinc-python).
For some example of the available predicates in the bp module, see my http://hakank.org/picat/v3_utils.pi . Also, see http://hakank.org/picat/#v3 for some examples of ported Prolog programs.