https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom;TicketID=11151931
I was informed that v6.3.2 had fixed the hard lock when using 3D Touch...however it is still bugged. I'm not sure the precise details of how 3D Touch is supposed to work, but as you can see, it randomly selects text and then it doesn't, and freezes after 20 seconds.
See attached video from user.