Hello, guys. I have a question.
Well you lock into any of the 4 LI's late in the game so I'm not following the problem, you can chose a LI at the earliest in chapter 12 but you can leave the decision for the last chapter 15. You can miss I think 1 scene in chapter 13 with Victoria if you didn't chose her in chapter 12 (checking the PDF WT from MrBubu). Played a bit ago but don't remember any consequences by "going for several girls at once", actually I remember I got also all the side girls scenes and still was able to chose one of the LI's in chapter 15 or none to get the alone ending. Of course some events always can require some stat or variable to trigger, if you make many "wrong" choices some events may not trigger, that is why I prefer to use a guide when I have doubts what is the "right" choice.
I followed MrBubu PDF walkthrough mostly when was available (it isn't the one in the OP, that one I find it harder to follow and to read, I can give you the MrBubu pdf wt link if you want if you can't find it by search) and the multi mod that is in the OP when the PDF wasn't. Then in chapter 15 you chose one of the LI and get her ending. There is kind of a secret ending that is harder to get because it have some specific requirements, it is an alone ending where you have a scene with Victoria and Gloria and an extra scene too. So there is the 4 LI endings and the normal alone ending and a special alone ending.
The game is completed for a while now, not gonna bother with spoiler boxes.