Based on international incidents. Can anyone name the last time a country shot another country’s manned aircraft during war games? Many rival countries observe each other’s war games. I am sure Iran observes The Arabs across the PG and the Azeri’s and the US when they conduct their own ones.
Even the Global Hawk (not during a war game) was a calculated move (and they didn’t hit the ENIT/SIGINT plane right next to it) due to Trump’s maximum pressure campaign and shadow war across the Middle East.
I think the only country that might actually do such a thing and break the norms is North Korea and that is because they know SK is a western vessel state and won’t do anything. Plus they know SK wont risk war (potentially nuclear) over such an incident.
When was the last time a multi hundred million dollar US asset was either shot down or taken over and landed? Also when was the last time a US military base was blown to cinders causing hundreds of casualties? I believe the answer to those will answer your questions. Iran does NOT play by the rules of her opponents. As such, conventional precedent means little.