Premaniplexes of rank $3$ and $4$ as symmetry type graphs of maniplexes

We show that every finite premaniplex of rank $3$ or $4$ is the symmetry type graph of a finite maniplex, settling the finite rank $3$ and $4$ case of the maniplex version of the symmetry type graph problem. The proof uses the fact that the universal string Coxeter groups of rank $3$ and $4$ are amalgams (of finite groups), hence they act on a tree, which allows us to use a lifting theorem of Potočnik and Spiga.