xModelSnapshot.cs not respecting '--output-dir' parameter for 'dotnet ef'?

Start by reproducing the documented dotnet ef migrations add command with --output-dir and inspect the verbose paths for the migration and DatabaseModelSnapshot.cs. Trace the migration output and snapshot-writing entry points, then verify with a focused test or reproduction that the documented output-directory behavior is consistent for both files, or identify the documentation change required.

Related but not the same issue? #10036

The documentation at Entity Framework Core tools reference states:
--output-dir <PATH> - The directory use to output the files. [...]

However when running:
dotnet ef migrations add InitialCreate --project src\Infrastructure --startup-project src\DatabaseMigration --output-dir ..\DatabaseMigration\Migrations --verbose

Only the migrations files are put in the output directory. My DbContext is called Database, and the file called DatabaseModelSnapshot.cs is put under src\Infrastructure\Migrations\DatabaseModelSnapshot.cs.

Is this a bug in the dotnet ef code, or an error in the documentation?

Verbose output:

dotnet exec --depsfile xxx\src\DatabaseMigration\bin\Debug\net5.0\Application1.DatabaseMigration.deps.json --additionalprobingpath C:\Users\my-user\.nuget\packages --additionalprobingpath "C:\Program Files\dotnet\sdk\NuGetFallbackFolder" --runtimeconfig xxx\src\DatabaseMigration\bin\Debug\net5.0\Application1.DatabaseMigration.runtimeconfig.json C:\Users\my-user\.dotnet\tools\.store\dotnet-ef\5.0.3\dotnet-ef\5.0.3\tools\netcoreapp3.1\any\tools\netcoreapp2.0\any\ef.dll migrations 
add InitialCreate --output-dir ..\DatabaseMigration\Migrations --assembly xxx\src\DatabaseMigration\bin\Debug\net5.0\Application1.Infrastructure.dll --startup-assembly xxx\src\DatabaseMigration\bin\Debug\net5.0\Application1.DatabaseMigration.dll --project-dir xxx\src\Infrastructure\ --language C# --working-dir xxx --verbose --root-namespace Application1.Infrastructure
Using assembly 'Application1.Infrastructure'.
Using startup assembly 'Application1.DatabaseMigration'.
Using application base 'xxx\src\DatabaseMigration\bin\Debug\net5.0'.
Using working directory 'xxx\src\DatabaseMigration'.
Using root namespace 'Application1.Infrastructure'.
Using project directory 'xxx\src\Infrastructure\'.
Remaining arguments: .
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Finding application service provider in assembly 'Application1.DatabaseMigration'...
Finding Microsoft.Extensions.Hosting service provider...
No static method 'CreateHostBuilder(string[])' was found on class 'Program'.
No application service provider was found.
Finding DbContext classes in the project...
Found DbContext 'Database'.
Using context 'Database'.
Database is not configured. Configuring from environment..
Finding design-time services for provider 'Microsoft.EntityFrameworkCore.SqlServer'...
Using design-time services from provider 'Microsoft.EntityFrameworkCore.SqlServer'.
Finding design-time services referenced by assembly 'Application1.DatabaseMigration'...
Finding design-time services referenced by assembly 'Application1.Infrastructure'...
No referenced design-time services were found.
Finding IDesignTimeServices implementations in assembly 'Application1.DatabaseMigration'...
No design-time services were found.
DetectChanges starting for 'Database'.
DetectChanges completed for 'Database'.
Writing migration to 'xxx\src\DatabaseMigration\Migrations\20210308082724_InitialCreate.cs'.
Writing model snapshot to 'xxx\src\Infrastructure\Migrations\DatabaseModelSnapshot.cs'.
'Database' disposed.

Version info

dotnet --version: 5.0.102
dotnet ef --version: Entity Framework Core .NET Command-line Tools 5.0.3