Depends, only if you are going the Quinn route maybe atm.
For me the OTHERS route is more of the same from 1-8, where you get to explore options and maybe get original LI's in a different way later on. Same goes for picking a relationship, you can still be a DIK and cheat the LI.
The game doesn't lock you per se with being a man whore. Only real hard lock so far is Jill/Quinn.
And for the moment, just the main girls are locked, which makes sense due to being in a relationship with one of them.
Imo, the split happening at around chapter 10 makes sense to me, since the game will focus on fallouts of said romances(can a threesome be maintained, breaking them up, Bella's Ex, Josy's dad, MC's background and Jills). With getting a relationship out of the way now, the game gets to focus more on the main plot. Which I honestly prefer over 5 more chapters of dating.
I'm ok with things as they are, and would prefer things to move forward and not stay the same. 2 Seasons of dating is enough for me tbh.
This is of course, my personal preference/opinion. Too each is own of course