That's how the default game is. You can of course just load up a save just before you picked your second path and try the other one to see which you like more.
I use the mod and it works fine. In fact,
LightmanP is one of my very favorite modders. a) he tells you what you are gonna get (points, variables changed instead of just arbitrarily marking a choice green), b) gives you a choice to see both if there are variants of the same scene (e.g. Dom path vs Love path), and c) In this game, not only lets you investigate all 3 paths but the alternate sub-routes within them as well e.g:
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If the intent is to see as much content as you can in a single play-through, this mod is as good as it gets.