Coercive field (Ec) engineering based upon the monovalent Rb+ ion (Rb/K/Ba-exchange) and the divalent Ba2+ ion (Ba/K-exchange) has enabled the reliable periodic poling of RbKTiOPO4 (RKTP) for quasi-phase-matching (QPM). Previously, there have been no systematic studies to understand and compare the changes in polarization-switching properties induced by these two families of exchanges. In this paper, we compare different compositions of Rb/K/Ba- and Ba/K-exchanges in terms of how they affect the polarization-switching time, ts, and ionic conductivity in RKTP. We discuss the change in switching time, ts, that is ascribed to the interplay between the monovalent and divalent cations in the exchange. Moreover, we propose exchange-induced strain as the cause of bulk phase-matching shift and show that exchanges containing lower amounts of Rb induce less strain. This is corroborated by strain-deformation measurements on the exchanged samples. Finally, we demonstrate highly efficient periodically poled RKTP crystals free of bulk changes, using two different high ts - low strain exchanges.