Assuming you are going to leave the rear O2 installed and the codes for it enabled (as they are stock); if you set the Cat Diagnostic DTC(s) to "No MIL", the test will run 1 time, set the Cat DTC, and then future tests will not run.
If you disable the Cat diagnostic codes completely, the PCM may attempt to run and re-run the tests, but I would THINK it should immediately discontinue each test as soon as it sees that rear O2 sensor go rich. I do NOT know if it will keep trying to run the test of if it will discontinue running tests for that key cycle because I never had the chance to try it.