The Local directory appears to be a development remnant. It is unused in release versions and is not present at all on Switch.
Identical to the regular Content/System/RegionLangMask.txt on Wii U. Unused in release versions.
Analysis of the executable reveals that during development, ActorInfo.product.byml was loaded from Local/ActorInfo.product.byml.
In release versions, the game will still load from Local if a debug heap is present in the init parameters (sead::Heap* at offset 0x8) or if a flag is set in the GameConfig structure (bool at offset 0x3d0).
- The check is located at 0x7100F3B694 in Switch 1.5.0