Merge instances from the filesystem and project?

[LPGhatguy]

Given this node from a project:

"ReplicatedStorage": {
    "$className": "ReplicatedStorage",
    "$path": "src/ReplicatedStorage",
    "$ignoreUnknownInstances": true,

    "Subfolder": {
        "$path": "src/ReplicatedStorage/Subfolder",
        "$ignoreUnknownInstances": true
    }
}

If src/ReplicatedStorage/Subfolder exists on the filesystem, Rojo will currently create two instances called Subfolder and cause all sorts of weird havoc in Roblox.

Instead, Rojo should probably merge the two instances. This would let users overwrite properties on deeply-nested instances specified on-disk!

[LPGhatguy]

This should be fixed by init.meta.json and friends instead.

[Kampfkarren]

This is a blocker for me, but implementation is pretty complicated FMPOV.

• It needs to merge the instances...
• ...while also preserving their metadata
• ...and not locking properties like $ignoreUnknownInstances on the entire child but only for those in the scope of the partition(?)

[Kampfkarren]

Suggested on Discord: only merge Instances if they're both folders. Otherwise, blow up?