OK, how do you tell if someone is actually injured and requires treatment or is just faking?
How do you balance the desire to keep play going and not have tactical stoppages with ensuring you don't have a player packing into a scrum or similar that should be receiving treatment?
I use the example of the Cheetahs a few years back: same prop kept going down, ice pack to the neck/shoulder etc.
For the first one, then OK. If he's THAT injured, get him off the field at the second bite, and we're done here.
It won't happen overnight, but it *will* happen.
For any position outside the tight five, play on until it becomes an issue for general play to continue.
We can talk about duty of care all day, but the player knows when they're injured or not, so they need to accept responsibility as well.