get-mcasfile -extension cannot retrieve multiple file extensions in a single call

[silviews]

Call get-mcasfile -extension "jpg" works, but would be useful to have multiple extensions in a single get.
get-mcasfile -extension "jpg", "docx" etc. (similar to fileType)

Limits the results to items with the specified file extensions, such as 'jpg', 'txt'.

    [Parameter(ParameterSetName='List', Mandatory=$false)]
    [ValidateNotNullOrEmpty()]
    [string]$Extension,

    # Limits the results to items without the specified file extensions, such as 'jpg', 'txt'.
    [Parameter(ParameterSetName='List', Mandatory=$false)]
    [ValidateNotNullOrEmpty()]
    [string]$ExtensionNot,