formatting unavailable inside interpolated subexpression

Formatting doesn't seem to occur for code contained within an interpolation:

In this example, the other 'else' statements just reformatted, but the remaining ones are inside an interpolation. It appears no formatting occurs in this condition, not even via using a selection (in VS Code). I use a lot of complicated interpolations. This code comes from https://github.com/msftrncs/PwshJSONtoPList/blob/master/ConvertTo-PList.ps1

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      6.2.0
PSEdition                      Core
GitCommitId                    6.2.0
OS                             Microsoft Windows 10.0.18890 
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}        
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

> (Get-Module -ListAvailable PSScriptAnalyzer).Version | ForEach-Object { $_.ToString() }
1.18.0

まず、issue の PowerShell の例にあるフォーマット動作を、VS Code での選択も含めて再現し、PSScriptAnalyzer の formatter が補間された部分式をどのように処理するかを調査します。補間内のコードが周囲の else 文と一貫した形式でフォーマットされれば完了です。