Each model unit has its own set of software updates and they should not load the other model’s update. Even different models like the 798c Si, 798ci Si and 798ci HD Si all have different software update files and they should not load the other unit’s update file. Even if the update files are for the same revision number (Ex: both are 6.300) they are different files for different units.
The 798ci Si and 798ci HD Si are the only 798 models with “ci” in their model name (excluding the different international models here), so I would assume that these are in fact the same unit and same update file.