The real Poll or [POLL] text will not be displayed at all as all formatting will be removed by default.
Actually that's what I prefer - only [POLL] or [HTML only] text is enough for me, I don't need the actual poll or other formatting in the Checker.
The code mentioned is great for moderators and admins as all links and formatting are displayed as it is in the checker and they don't have to cross-check with the posts in the forum.
Well, I would argue with that..
* What if the message is long (like 1000-2000 characters) - in the preview you'll still see only a part of the message (what if the links/poll/picture/videos are posted at the end of the message - that way you'd still have to check the actual message, UNLESS you set up that you want a preview of 2000 characters, but then the checker file of each member would be very large, the page would be very long, and it would slow the exectution overall)..
So I think I prefer the default option and it works well for me (but for you the custom change may work well too :).