I did mean "region" in my example so apologies for that. While its true that you do say "usually" in the description, you also note that "all journey checks are made at the beginning of the region". So in theory the party still has to "plan out" all of their journey activities at the beginning.
I did try at first doing the rolls but then "retconning" if a player changed their mind based on what came out, but that was messy and gamey. Player gets a critical success on the roll and then decides "well that's day 1 I want to do something else". Ultimately I switched to daily rolls for the journey activities, which was more tedious but addressed the narrative problems I mentioned. However, that has its own problems, as now the chances of getting critical successes and critical failures are significantly higher if I'm rolling 10 checks rather than just 1.
What I then houseruled to solve that problem was: "only one critical failure and critical success can be generated per journey task per region". So if the cleric critical fails their prayer on day 1, they can't critically fail on the other 9 days through the region.
So you can see how the issues somewhat cascade, and that's ultimately my feedback. The journey system really didn't feel like a polished "system". As you said, its more of a "suggestion" on how to do things, but that wasn't what I was looking for in a crunchier 5e rules type book that LU was marketed as.
OH that does remind me (something I forgot in the original feedback). I believe the errata around Pray is incorrect. I believe you intended that to be for the "critical success" area, but it's stated as the success area.