Nokia Lumia 520 on Koodo ROM with Windows Phone 8.1 also has field test, so this should work. Though I don't see it being an issue in Canada, no 2G (Where I live at least).
Ohoh, read.... Vietnam supports FT.
For you 059T4P9 RM-875 VAR APAC VN CV BLACK
Try this Product Code of Australia 059V5K1
---------- Post added at 05:52 AM ---------- Previous post was at 05:21 AM ----------
Try this code of australia 059Q9Q0, This firmware allows only enable 3G and 4G
Use 059V023 RM-875 VAR APAC AU OPTUS BLACK
##3282# is normally available.
We can not know until we have not tried
For me for example, my 920 (059Q8C2 = VAR EU FR) Field Test still works on WP8.1.
Lumia 520
059S357 RM-914 VAR VN CV
Lumia 525
059V486 RM-998 VAR APAC VN CV
Lumia 620
059R2C9 RM-846 VAR VN CV
Lumia 625
059T4N6 RM-943 VAR APAC VN CV
Lumia 720
059S380 RM-885 VAR APAC VN CV WHITE
059S362 RM-885 VAR APAC VN CV CYAN
059S363 RM-885 VAR APAC VN CV RED
059S361 RM-885 VAR APAC VN CV YELLOW
059S360 RM-885 VAR APAC VN CV BLACK
Lumia 820
059Q998 RM-825 VAR APAC VN CV
Lumia 920
059Q8Z9 RM-821 VAR APAC VN CV BLACK
059Q8Z8 RM-821 VAR APAC VN CV GREY
059Q902 RM-821 VAR APAC VN CV RED
059Q901 RM-821 VAR APAC VN CV YELLOW
059Q900 RM-821 VAR APAC VN CV WHITE
Lumia 925
059S6W4 RM-910 VAR VN CV BLACK
059S6Z1 RM-910 VAR VN CV GREY
059S6Z0 RM-910 VAR VN CV WHTE
Lumia 1020
059T4P9 RM-875 VAR APAC VN CV BLACK
059T4Q0 RM-875 VAR APAC VN CV WHITE
059T4Q2 RM-875 VAR APAC VN CV YELLOW
Lumia 1320
059V569 RM-996 VAR APAC VN CV
Lumia 1520
059V317 RM-937 VAR APAC VN CV BLACK
059V319 RM-937 VAR APAC VN CV RED
059V318 RM-937 VAR APAC VN CV WHITE
059V320 RM-937 VAR APAC VN CV YELLOW
nnnnnnnnnnnUseless, because: http://xdaforums.com/showthread.php?t=2515453
In more, some of your images are poorly integrated and there is no link provided to download the required softwares.
thanks for this. i know i need to back up but will i lose all my apps after downgrading?
820 is lte, cant we also select 4G only in field test?