why use a tuner if there's an instrument present that can't conveniently be tuned, eg melodian or whistle.
A recorder can tune, but only downwards, and that puts it out of tune with itself.

Both recorders and whistles can tune upwards by using more breath. A player who doesn't understand that isn't somebody you want to be playing with. (There are a couple of local sessions I don't go to any more because they have a regular whistle player who refuses to get it).