"Add the complete email into the attachments" will not add the html to the attachments. It will add the complete email including its plain text, html and attachments as an txt file in the attachments. Its purpose is debugging

Adding the html version of an email to the attachments will work as far as to convey the general mark up of the email (like table layout and the information) but stuff like embedded images will not be shown so it will only be a partial solution.

Is that acceptable?

It is acceptable. I have discussed this with my colleagues and we find the parsed text should be enough.

Alright its added to the todo list. Can't say when it will be added though as the list is pretty long and i do not have a lot of time to work on this

These days EmailReporting 0.11.0 and later versions parse html emails to markdown (if enabled) and uses that for the description.
This should suffice based on your description as it will have markup like html.

Reopen this issue if it does not or having problems with this functionality