So I finally got to play a bit tundra, and oh my oh my, I am in love.
On a serious note, I think they did implement the looking for tracks of the musketeers very well. It sounded like its gonna be a nightmare of looking up guides where you might have missed one in this huge areas (USUM with Zygard cells), but it was super awesome and rewarding instead, as there are seemingly way more than you need to find.
As usual annoying though how you always have to chose between this-or-that though. Several examples, don't want to spoiler too much though