Aspects related to driven nonequilibrium systems considered in Beck-Cohen superstatistics (BCS) formalism and, in addition, the unbiased maximum entropy density estimation, show the pertinence of considering the three-parameter Burr-type-XII distribution as a suitable way to describe stationary states of complex and nonequilibrium systems. The above is shown following a variant to the procedure presented in the formulation of BCS, which consists of the incorporation of an expanded Boltzmann factor through the Mittag-Leffler function. On the other hand, maximization of Shannon-Boltzmann-Gibbs entropy and other generalized forms of entropy show that the Burr-type-XII distribution may emerge as the least informative distribution for the mentioned systems.