This issue has been closed as 'Won't Fix' due to an extended period of time without updates. If this issue is important to you please let us know by posting on the AnswerHub or UDN, and Epic will re-open the ticket for further review.
Cannot redock designer tab after the tab has been hidden. There is no way to get the tab back for the designer tab after undocking it and hiding it
Expected: There would be a way to bring the tab back after hiding it
Result: There is no way to get the tab back for the designer tab after undocking it and hiding it
Head over to the existing Questions & Answers thread and let us know what's up.