You have the same question as the person in a couple messages below. You have faced the desire to unlock some special scenes and you followed a reasonable but wrong path to achieve it. Yes, choices through the route are very important, but sometimes that's not enough. Most of the scenes you are looking for can misrepresent the first impression of the side characters of this route. To discover such content, you need to be familiar with this character. It's quite logical, isn't it? In your case, it is Chester. Maybe it's worth going through his route first, get closer with him, and then return to Dozer's route? What if it changes something?
(btw, despite the fact that I went through each route several times to see different endings and now digging into the game code, I didn't even assume that there were such scenes before you mentioned about them
)