Just a proposal for a restart *on in Ninja Exam, Team Instance, Survival Trial, and Strong Approach along with any other applicable places. The *on would let you start the match over from the beginning without having to retreat and go through the menus to get back into the fight. For things that possible requires teammates(SA, TI) then when the team leader presses the restart *on there'd be a popup similar to being asked about duels or team invitations.
Now to prevent spam or abuse for this, the restart feature would only be available for request once per run which would refresh assuming the request is accepted. Also, the restart would have to be unanimously accepted.