My experience is that the DNGs are clean and usable, ie no artifacts.
BTW I'm using a 5DIII.
My workflow for a fixed exposure timelapse is:
- a-ETTR to set exposure, ensure in manual mode and take note of Exposure values
- set intervalometer
- capture DNGs
- do holy grail adjustments if require. I only adjust my 1 stop so I know what the jumps are
- correct EXIF data in EXIFToolsGUI, having noted the key frame changes. This step is a little labour intensive if you used holy grail adjustments
- upscale if you wish to, ie more pixels for virtual panning
- use LR, LRTimelapse and Panolapse