Does not matter of the truck brand, the engine and emissions system is what dictate the regen.
The system sensors are the controls. If the DPF is really dirty, it could go for some time. Have seen ones take almost 2 hours. If it is requiring to do parked or computer forced regeneration, you may have a problem that needs further investigation.
As a general rule if you need a parked/computer forced regen or it takes a really really long time then just plan on a dpf filter clean pretty quick or else plan for a hook and then a clean and maybe other stuff too.
You hit the nail on the head! After the Regen everything looked normal until I merged back onto the highway and all the lights started going off again. I'm currently waiting for a tow truck to get me to a Peterbilt.