Opening .eml attachments in a calendar event on the iPhone and iPad?

Is it possible to open an .eml attachment in a calendar event on the iPhone and iPad? EML Viewer was the obvious choice but apparently iOS (and iPadOS) do not support this and won’t pass the eml attachment to the application.

I suspect it is not possible?

On my iPad, when I edit an event that was created from an email, I have the option to “Show in Mail”. This opens that email in the Mail app.

OK, it works if you create an event from an email, how about when you attach an email to an event?