Lineage OS : SD card as internal storage I have set SD card as internal storage on custom ROM Lineage 14.1. Today, I have installed a official nightly, no issues during installation(on twrp, I cannot read external SD card). And, after reboot the file explorer, shows only internal storage(external SD shows only in Settings->Storage). 


Do I need to migrate data to shared SD card, each time, after Nightly installation?
Earlier, when I set SD card as internal storage, I moved about 700+ MB to shared, and after nightly installation, it took 800+ Mb. 
Some applications can't move data to shared SD card (Whatsapp, Flipkart, Google apps). I know that it is decided by the android system. How to move them, without using root or any other application. 
TWRP Recovery sometimes rarely not showing external SD card.(TWRP version 3.1.0). How to solve?
After asking this question, I have installed two nightly on my device.


March_13 : lineage-14.1-20170313-nightly-armani-signed.zip
March_20 : lineage-14.1-20170320-nightly-armani-signed.zip 


Now, I can finalize something about this.


You don't need to migrate data after each installation(nightly). 


if it is a clean install(after factory reset), then you need to migrate data`.  
if you are installing another ROM, then you need to setup as new by formatting sd card.(backup before installation to avoid data loss)

Storage size may increase due to application data usages, but, you don't need to migrate it again.


If you are flashing another ROM, don't format internal storage(format these partitions /boot, /data, /system and cache. This adoptable storage cannot be used on the newly installed ROM, but it will be available during installation [on recovery menu]). 
Also, if you're backing up current ROM, Adopted SD card data is also get backed up, but the app that uses SD card as storage will loss data after restore (You need to install those apps again).   

System decides which applications should save data on external sd card.(usually system apps and Gapps can use only internal storage, some user apps can be moved to external SD )
External SD card speed is slower than internal storage. Also, it may be the bug of TWRP recovery, which will be solved in future new releases.