@doctormike,
Perdix will monitor Min PO2 and Max PO2 irrespective of whether you and I change the settings. If you don't change the settings, Perdix will just use default values. Those alarms are set. I don't believe that Perdix allows you to turn the alarms off. Understanding the theory, knowing where to find the settings, and having sufficient knowledge to change the settings away from default values does not mean that you are in any way more dependant on the computer. It just means that you know what the computer is doing and can change the default values to set it to be more or less conservative.
As someone certified 30 years ago before computers were readily available, I would be quite comfortable diving with a depth guage, bottom timer, and RDP. In fact, I used to have a credit card sized RDP that followed me diving. I believe that I would be able to execute a tec dive with a depth guage, bottom timer and dive plan (together with contingency dive plans in case planned depth and/or time are exceeded).