There's a workaround. You can add Bookmarks to Speed Dial and get access from there with one click.
"Add link" would not work, but if you edit an existing link (click on the 3 dots and Edit) in Speed Dial and change the url to opera://bookmarks/ that would turn it into Bookmarks.
Otherwise right click on any empty space of Speed Dial and click Bookmarks.
@tascha666 Currently it's not possible to have what you want. I the future, if and when Chromium supports it, maybe Opera and other browsers will have such feature.
Nowadays the closest thing would be to use a regular window and a private one to login in two different accounts of the same site.
You can do it for the current session manually by opening up a new tab, going to the URL opera://discards and turning off auto-discardable for the opened tabs you want.
Is it possible to give users the option to name the 'speed dial' folder, at the save to speed dial prompt?
Right now it's a pain to save to speed dial, then open a new speed dial window, scroll to the 'hopefully' saved speed dial folder icon, and then attempt to edit/rename the folder.
As a result, users end up having a lot of speed dial folders simply/default-ly named 'folder'.