After fix ZBX-15135 is live, the availability report page by trigger template will show only real non-discovered triggers. However switching mode to "By host", the discovered triggers can be selected. There must be a way to do this when viewing in other mode "By trigger template".

Currently the API will not allow a request to retrieve triggers discovered by a certain prototype.
Options:
a) Add an option to trigger.get method which would allow to select discovered triggers by given trigger prototype IDs. For naming we could use prototypeids.
b) Change the API request in report2.php to a complex SQL which is not a good idea.
c) Get a lot more triggers in results (could be a performance issue here) and filter out unnecessary triggers that way. Also not a good idea.