The J-PARC 3-GeV rapid cycling synchrotron (RCS) provides a high-power beam to both the materials and life science experimental facility (MLF) and the main ring synchrotron (MR) by switching the beam destination pulse by pulse. To meet different requirements from the MLF and the MR while keeping beam loss within permissible levels, the RCS has recently introduced a pulse-by-pulse switching of the operational parameters such as injection painting emittance, chromaticity and betatron tune. This paper reports such recent efforts made for the performance upgrade of the RCS.