Hello Tony,
We are also "impacted" by this.
We were looking for a way to have the ticket content displayed in HTML by default (if html contrent available), but it seems such an option it's not available.
We use the "Show HTML" but it would be convenient for us that the HTML content is displayed by default.
After some thought, I assumed that it is not possible to display HTML by default but on line in a separate window, to avoid for example javascript injection in the HTML content of the mail that could be a security issue ?
If yes, maybe adding a filter that strips javascript out of the content could be a viable option ?
Anyway it's not a huge problem for us but more a quality of life improvement :)
Kind regards