The adoptable storage option implemented from Android 6 allows to use the micro SD of a device as internal storage. Samsung disabled this feature on the Android 6 system that the Samsung Galaxy S7 originally came with , but even though it can be enabled through a simple process, it may not be worth it..
The main advantage of converting the micro SD into internal storage is to be able to install or move applications there, which is not normally possible if the SD works in "normal" mode. Although in the Galaxy S7 the adoptable storage can be enabled through the ADB utility and the command sm partition DISK TYPE RATIO , the users of this device may NOT have to do it due to all the disadvantages that occur when configuring the adoptable storage and also because the Galaxy S7 already allows moving applications to the SD card.
Move apps on the Samsung Galaxy S7. Source: Droid Life
The option to move applications to the SD of the Galaxy S7 is apparently as good as the adoptable storage of Android 6: the main similarity is that you can completely move the applications to the micro SD (Application and Data)..
The adoptable storage has several problems: mainly the fact that the micro SD cannot be used in other devices after being configured in this way. I don't know why a Samsung Galaxy S7 user would want to activate the adoptable storage after all that was said, but in case it is so, it would be good to consider not using all the capacity of the micro SD as adoptable storage, but only part of it. her and the rest for portable file storage (normal SD working mode). This would provide the best of both worlds and eliminate the downsides of adoptable storage. The link below teaches how to partition the micro SD for adoptable and portable storage (basically, it's all a matter of using the ADB tool and the command sm partition DISK TYPE RATIO indicated above).
Adoptable storage on the Galaxy S7 and S7 Edge : Modaco
How to set the SD card as internal memory
How to expand the internal memory of a cell phone (LITERALLY)
How to transfer apps games to SD CARD