I feel like I'm missing something obvious, but I am trying to create a race in the editor, replacing the existing spells from an existing race, and I can't find where the edit would be entered. I've edited the text describing it, and I thought I remembered the mechanical edit being entered below that, but I can't seem to find it. Has the display for that been changed?

No, nothings been changed. You would have to expands the “Spells” section of the racial trait and edit it there. Try turning your phone sideways or widening your display.