I know this a bit of an old thread, but I wanted to resurrect the idea of changing DRL settings like this at home. I purchased a vehicle that has the ability to turn off DRLs with the switch, but in Canada, they are required to be non-switchable. I came across the FORSCAN software and currently have the extended license that allows for changing settings like this at the code level.
I am currently trying to track down the actual setting that changes this on or off. If anyone knows the code to look at, please let me know, otherwise I will look to update this thread once I have it figured out.