The 3.9E (English version) is the same regardless of where you get it. What you will not get is the instruction sheet with the update info.
I have installed it and tested it on both my 18SZ and 16SZ in both single and dual receiver modes. Works great.
You need to re-link the RX after the update, and you have to do that as if it was the first time you linked it.
1) go to LINKAGE->SYSTEM TYPE
2) Tap the system type you are using in the current model (18-ch FASSTest, 12-ch FASSTest, or T-FHSS)
This clears the currently linked RX info, but does not affect the model data.
3) Select the System type again and then link like normal.
Note: This only works with FASSTest and T-FHSS receivers. It does NOT work with FASST of SFHSS receivers.
I have no idea when it will be listed on the FutabaUSA site, but I suspect it will be fairly soon. That will have the English instruction sheet. Also note that each update contains all previous updates as well.