Hello and thank you for using Just Answer. I would not waive the statue of limitations in any way, shape or form if I have substantial authority for the deduction. Less than 5% of taxpayers who file for a office in compromise get approval and the penalies are not set by the agent. The third alternative is the one you should choose.
If it is to your benefit to give more time, they you will want to give IRS a reasonable extension. If the case is going to appeals you will need to be sure that appeals has appropriate time to work the case.