  The paper presents a detailed analysis of the so-called "Double-Root
Tangent-Polynomial" (DRtTP) reduction of the regular Gauss-reference (r-GRef)
potential exactly solvable by hypergeometric functions. It is shown that the
Dutt-Khare-Varshni (DKV) potential represents a remarkable particular case when
the DRtTP r-GRef becomes expressible in terms of elementary functions. This is
also true for its basic single- or double-step SUSY partners which are either
exactly or conditionally exactly quantized by Heun polynomials (Hp-EQ or
Hp-CEQ, respectively).
