Oh, for sure!
A lot of smaller things. There are smaller things in the first couple chapters that are kinda problematic because I didn't know better at the time, and there are places where I see now how I could've set things up better -- I definitely had time to set up the idea that the blood aberrants' heart is vulnerable before they were fighting a blood aberrant, and that would've made the end of that fight much smoother, narratively, for example.
Every time I post page 1.23 somewhere it's hard not to apologise for it -- it's the biggest infodump in the comic, that taught me that in the future I really needed to think ahead when I know I'll need exposition later, and plan where I'm going to put it!
There was one scene I felt for a long time had set up one of the characters very poorly, and I was really unhappy about it for a while afterwards. Ultimately, though, my dissatisfaction with that scene helped me figure out what was important to show in that character in future scenes, and I feel a lot more assured of their direction now!
So yeah, there's a lot of little things I look back and think "DANG I coulda--!" but not like... not to the extent that I'm pining to go back and change it. Just things I see now that I coulda done better, but I learned from them, and now I know to do better going forward!