As hinted, this thread led me to revisit her and do some further adjustments like fixing paint chips and improving the skin tone to better match the head. Speaking of the head, I tried removing the yellow lines with alcohol and even a utility knife, but they wouldn't come off. Instead, all I could do was darken them using a pencil. The head was basically left as is for now.
What I thought was the masking tape showing through was actually what I used for the specks of glitter. I guess I didn't apply it very well. The biggest (and my favourite) change was adding the sequins to the bodice (something I should've tried to do when I started). This was done by cutting out small pieces of masking tape and applying them one-by-one until the surface was covered. It wasn't as tedious as it may sound and went fairly quickly, one reason being that some were longer than others. It looks much more like what she actually has, because the glitter alone didn't give the effect and the wrinkles ruined it.
Base coat applied. Some more blue will be added like the bottom, as well as the metallic gloss to complete the look. I'm highly impressed with the authenticity, and it should look even more splendid after shading.
Compared to the CGI model (on a Frozen poster that's been on my room door since 2018). I know the sequins should be a lot smaller, but I made them thicker to make them easier to cut and apply. The stock art makes it appear less metallic than in the film, so I'll base it on how it actually looks.