Recording of conversations that aren't protected by attorney-client privilege is standard procedure. If your system can't do that, you'll never get a contract.
You'll never get a contract, because if you aren't gouging, the (comparatively low) revenue sharing you do back to the prison means your bid will be the least appealing.
While we're at it, couldn't you make all the conversations protected by attorney-client privilege? Just have the lawyer host an acoustic coupler in their law offices. All calls are to your lawyer.