There is no option to change the label of the edit button when "Link to previous pages in preview" is selected

Currently, you can't change via the UI the 'Edit' button's label when 'Link to previous pages/cards in preview' is checked.

The 'Edit' button label is defined via \Drupal\webform\WebformSubmissionForm::pagesElement

I am hesitant to add any more features to the webform module especially when this edge case request can be accomplished via a form alter hook

Yeah I understand.
We just stumbeld upon this when a content creator was trying to set up a webform in a different language in a non multilingual drupal site.
Our distro doesn't support that at the moment but people always try to hack funny things.
So maybe we will use a config page and use a form alter hook to let them translate it in the UI somehow.

Closing this issue.