It has been a while since I was "in there" with my driver's DLA, but I recall
@AndrewWynn fixing his and concluding that one motor is for locking+unlocking, and the second motor is for double locking. I don't know what is right here, but maybe think about it some more.
The one general point I'll relay from having a few random, unrelated issues with the central locking system over the years on my 2001, is that it can be pretty amazing how a failure in one part of the system can cause symptoms in a very different place. So yes, if you're thinking that an issue with the driver's door window control module might be causing problems with the passenger side DLAs, I'd say in general, yes, consider that might be true.
My Foxwell was pretty useful in being able to manually command lock/unlock on the doors (left front, right front, both rear), although when doing that, it found weakness in the rear DLA actuation, which turned out to be due to an issue in the driver's DLA. Black magic, I tell ya.