SSMS_Settings.ps1

# Dark Theme
    $file = gi "${env:ProgramFiles(x86)}\Microsoft SQL Server Management Studio 18\Common7\IDE\ssms.pkgundef"; ($file | gc) -Replace '(.*{1ded0138-47ce-435e-84ef-9ec1f439b749})', '//$1' | Out-File $file;
# Query execution settings
    $ssmsUserSettingsFile = "$($env:APPDATA)\Microsoft\SQL Server Management Studio\18.0\UserSettings.xml";
    $newXml = "<Element><Key><int>-1</int></Key><Value><string /></Value></Element>
               <Element><Key><int>3</int></Key><Value><string /></Value></Element>
               <Element><Key><int>4</int></Key><Value><string /></Value></Element>
               <Element><Key><int>5</int></Key><Value><string>USE </string></Value></Element>
               <Element><Key><int>6</int></Key><Value><string>SELECT FORMAT(COUNT(*),'N0') FROM </string></Value></Element>
               <Element><Key><int>7</int></Key><Value><string>SELECT TOP(100) * FROM </string></Value></Element>
               <Element><Key><int>8</int></Key><Value><string>SELECT * FROM </string></Value></Element>
               <Element><Key><int>9</int></Key><Value><string>SELECT </string></Value></Element>
               <Element><Key><int>0</int></Key><Value><string /></Value></Element>"
    # Open file
    [xml]$xmlDoc = gc $ssmsUserSettingsFile; $QESettings=$xmlDoc.SqlStudio.SSMS.QueryExecution;
    # Set Settings
    ($QESettings.SelectSingleNode("QueryShortcuts")).InnerXml=$newXml;
    $QESettings.ExecutionSettings.SetTransactionIsolationLevel="READ UNCOMMITTED";
    $QESettings.ExecutionSettings.SetDeadlockPriorityLow="true";
    $QESettings.ExecutionResults.RetainCRLFOnCopyOrSave="true";
    # Save file, then re-open and save to format
    $xmlDoc.Save($ssmsUserSettingsFile); [xml]$xmlDoc = gc $ssmsUserSettingsFile; $xmlDoc.Save($ssmsUserSettingsFile);

[reserving first comment]