Some weeks ago I requested a feature where phoenix stops mining if it cannot find addressed card in config, this is becasue I have a mixed rig and sometimes one card goes missing due to a riser problem or whatever, phoenix starts to apply wrong OC values to GPU's. Since I don't have hope that they even see the request, I made a simple powershell script that counts number of adapters and if you have the desired number of adapters, runs a batch (that runs Phoenixminer in my case) or runs another batch if it can't find the required number of GPUS (of course the batch sends me notifications so I can keep track.) You can use this to either shutdown the system cleanly, or if you want you can run your miner with safe settings that matches all your GPU's.

You can find the script here:
Powershell script to run batch based on display adapter count

You can place the .cmd file in shell:startup, but since I need admin priv. for AMD mem timings I use task scheduler to run the script at startup with admin privileges.