I was nervous when I realized the MFL was replaced due to the story progression. I wouldn't say the FL was "recast" since this actress also played the same character in the first season, but she comes back in season 2 to take center stage.
First, the lead actress here is an absolute delight. I LOVED the main actress from the first season, she's one of my favorites, and I missed her funny facial expressions and sass in this season, but I didn't feel overall upset or like I missed out. In the end, and given the direction of the story, the new actress (who, I guess, isn't technically new) was phenomenal and brought her own color to the character which was neither better or worse than the original, just different.
The ML was awesome, as expected, and a bit darker in this season, which I loved. It was great to see his character mature and struggle in new ways.
The lovestory and overall story arc felt rushed, however, and that's why I had to take off a half star. If this had been 2-4 more episodes, where they spent more time building the narrative, it would've been an easy 10.