  In a recent work Chiu proposed to modify domain wall fermions that allow in
an optimal way fewer number of flavors than in the standard case. This is done
using a variant of doamin wall fermions, the so-called truncated overlap
fermions. In this note I discuss the possibility to implement his proposal for
the original variant of domain wall fermions. I make also some remarks on
dynamical simulations with ultraviolet suppressed domain wall fermions.
