With the new 3.2 update, will I be able to transfer movies and tv shows to the Shield TV (either an external HDD or the internal storage) from my computer.
With the new 3.2 update, will I be able to transfer movies and tv shows to the Shield TV (either an external HDD or the internal storage) from my computer.
Nope. You can only access the storage of the Shield device itself.
Is it possible to have that write access plex folder on an external drive ?
Get a NAS.
Yes.
If it's internal, you can copy things over pretty easily, but I wouldn't recommend doing that.
If it's external, then you will have read access over the whole drive (via smb) and write access to one particular folder:
/Android/data/com.plexapp.mediaserver.smb/
But you can just store all your TV/Movies there and things will work just fine. You can access that folder from Plex or Kodi and either media player will work without issues.
https://forums.geforce.com/default/topic/948161/shield-android-tv/managing-external-drives-over-smb-/?offset=5#4916455