in my experience, I don't believe enable/disable undoes the under or overvolting, although I do perfer to do it after just to be sure.

I personally have Devcon autostart with windows.. Then OverdriveNTool start after it.

This feature of Devcon to start with SRBMiner will only become useful to me if we also add a restart miner on a drop below hashrate to monitor if the cards need to be enable/renable mid run..