In case there's someone that might want to flash their Xperia 1 AU/SoftBank into Global but also want to have VoLTE support, you can flash this Customized_UK firmware with Customized_SEA's oem files.
Download:
Google Drive (flash it with newflasher)
If you want the complete firmware, download this -> "J8110_Modified UK_SEA_55.2.A.4.332-R4C.zip"
If you only want the oem files, download this -> "SEA VoLTE Patch.zip"
- THIS IS ONLY TESTED ON XPERIA 1 AU (SOV40) WITH INDONESIAN CARRIER!
- THE NFC IS OF COUSE WOULD NO LONGER WORK, BUT YOU'LL GET VoLTE WORKING.
- DO NOT FORGET TO REMOVE ANY .ta FILES BEFORE FLASHIING OR YOU MIGHT RE-LOCK YOUR SIM! (this is purely just my assumption)