FiTech EFI system

I have a question about the timing control many of these EFI kits have. Its not really about Mopar ignition but any ignition be it GM/Ford or Mopar. I keep reading everywhere about how rotor phasing needs to be done when installing one of these kits with timing control and i am kinda baffled. Isn't rotor phasing something that should be done as part of the tuning process even with a carb set up? I understand an adjustable rotor would be needed when using an old carb set up as you would need to set the timing first, lock the distributor down tight then fine tune the rotor phase after timing is set. Why would you need to do all that with one of these Fitech EFI kits? (or any other of the kits out there that have the timing option) Why would you need an adjustable rotor with the Fitech kit? Why not just use a cap with a hole drill out and get your rotor phased perfectly on TDC of #1 and then lock distributor down before you even start the engine up. Won't the Fitech ECU then take control of the timing for you? Am i making any sence or am i just nutts :)