Cartoon illustrating the possible manners, as considered in this work, in which the primary mass distribution of a binary black hole might evolve with redshift. As illustrated in the left panel, we consider the possibilities that the location, width, and/or height of the 35 M_⊙ excess evolve with redshift (see Sect. 3.1). As illustrated on the right, we allowed for the evolution of the height, slope, and endpoints of the power-law continuum (see Sect. 3.2).