What figure formatting can, should, or will be done by a publisher?
For many years, the standard on the part of journals is to do absolutely nothing with respect to journal articles. Essentially all of the work in terms of preparation falls on the authors. Previously, figures had to be "camera-ready"; now, they "just" have to be publication quality. The journal production staff will not do anything, except potentially change the size of the graphic to better fit the column space.

You should check with the journal about the regulations on acceptable graphics; they should have them available for your review on their website. If there are questions about the use of graphics outside of those guidelines, send an email to the journal office.