Give it a try. You're still together as a group, you show up in all the cutscenes (unlike in split screen where half the time only the person who initiated the dialogue is) etc. I too thought it must be terrible when I first read that thread, but the two controllers make all the difference as it feels like you're both playing all the time.
Thank you for your suggestion and for your help, it is much appreciated. We tried it in the past and it's a small step forward, but unfortunately, it's still far from the DOS real co-op experience, where the beauty of it lies in doing different tasks at the same time. I consider myself already out since I uninstalled the game, but I'm still curious to know why Larian didn't say a word about it. Furthermore, they recently updated the Dual Sense key command guide in BGIII by deleting the indication of the down arrow as the command for merging the camera, like this function was somehow to be included but now it is completely deleted.