PDF-A and standard fonts (e.g. Helvetica)

Hi everyone

When enabling PDF/A ($options->set( 'isPdfAEnabled', true ) ) and using one of the standard fonts (e.g., helvetica), Cpdf throws an exception in processFont.

if ($this->pdfa && !file_exists($fbfile)) {
    throw new \Exception("A fully embeddable font must be used when generating a document in PDF/A mode");

Of course, this can be avoided by using a custom font or one of the DejaVu fonts.

However, if someone explicitly wants to use one of the standard fonts (such as Helvetica) and insists on it, is there any way to enable PDF/A anyway? Is it possible to make these fonts embeddable or otherwise compatible with PDF/A?

Any suggestions or guidance would be greatly appreciated.