A multi-reflection time-of-flight mass spectrometer (MR-TOF) will be a critical component for quickly removing radioactive contaminants produced at the future "N = 126 beam factory" addition to ATLAS at Argonne National Laboratory. This unique thermalized ion beam facility will employ deep-inelastic reactions to produce very neutron-rich isotopes relevant to the astrophysical r-process. This production method entails high levels of isobaric contaminants, but precision measurements of such rare isotopes typically require highly purified samples. With this problem in mind, an MR-TOF has been built and commissioned in an off-line test setup at the University of Notre Dame. These devices can accommodate low production yields and short half-lives of desired radionuclides, and can separate isobars with resolving powers > 10^5 with a non-scanning operation. A series of simulations done in symphony with the off-line commissioning, as well as a summary of the MR-TOFs performance, will be presented. This work is supported by the National Science Foundation and the University of Notre Dame.