Why would Iran want Trump dead in such a foolhardy way? If you assassinate him you galvanize the US in its resolve while removing the bozo at the top?
The US has lost, Iran controls the strait now and forever; the longer Trump is in the greater the loss will be.
Emotions. The US killed much of Iran's leadership and a lot of civilians (including a lot of children) at the order of Trump. That creates a strong motivation to do something, and revenge is one of those things that's emotionally easy to justify. Especially during war.
It seems as if the optimal outcome is to give every appearance of an assassination plan, and use that appearance to troll Trump.