You are going in a completely different direction to I. Read the definition of simulation in law. You are taking just one instance. I have caution for simulation plenty times after contact.
The law requires you to be able to tell if a player is feigning injury, whether qualified or not. Sometimes it's to deceive you to make a decision (sanctions) sometimes it's making it look worse than what it is to just to waste time.
I don't disagree, I know what the law but its a lot easier when obvious.
But if you have already been deceived into a caution we are a step ahead from that point. If you are saying to a player, do you need treatment/assessment I assume we are already at the point where we believe they are potentially injured.
Assuming, without proper knowledge or assessment that a player is feigning injury, after being on the receiving end of a challenge that endangered their safety or had disregard to the consequences for them, is a pretty dangerous game.
Yes, there will be grey ones, eg careless but SPA where the law about stopping on is applicable and I know its not a catch all and there will be edge cases, of course. But as a general rule, we only have our eyes to inform us, and that is not enough, medically, to determine if a player is injured enough to enforce the stay on the field rule.
I think I have only seen a player in the top levels once booked for feigning/embellishing injury which was Messi after being hit by a bottle.
I would add also, at most proper grassroots, its a bloke with a bucket and sponge with no first aid training so perhaps I am looking at this from the level I generally operate at where there are, mostly, proper physios.