On other cars I've used cheap AliExpress remotes, they can be hit or miss so I'm not a fan of using knockoffs.
Good quality key fobs for Fords seem to be made by Strattec, the OEM key fobs are made by Continental but you cannot buy them anywhere. With the FCC ID on the EU key fob (M3N-A3C108397) I was able to find out that this corresponds to a Strattec 5945817 / 164-R8333, a generic Ford fob but with the additional panic and remote start buttons running on 433 MHz.
The Mustang key fob with the additional buttons should be the Strattec 5945957 / 164-R8347.
Can anyone confirm that the panic button also works on a EU model? I'd hate to have a dead button on a new expensive key fob like that.