In ZBXNEXT-1286, there has been added a very nice feature to use LLD macros in trigger prototypes. However, I would recomend extending (or altering) the specs for one more requirement:

In "Details" section I would recommend following alteration (mine in capitals):
"If a macro cannot be expanded (no value or non-numeric value), a real trigger will not be created, OR IF TRIGGER ALREADY EXISTS, IT WILL BE REMOVED"

Reasoning:
AFAIK, In case we no longer need the trigger and we still need the item (with its history), there is no nice way how to remove the it. The only (ugly) way how to deal with it, is to change the threshold to an "always OK" value.