Does VA, EZ, or others hook into temp sensors or do they just run a defined fuel/ timing based on boost regardless of temps? I just keep reading posts about problems with these in cold temps and was curious to the cause.

I'm assuming that the ecm changes fueling/timing based on temperature. If so then one of the advantages of an aftermarket ecm as opposed to a fueling/timing box would be running in cold temps. And of course the advantage of a box would be the ability to turn it down or off in limited traction scenerios.