How about this. Medical forfeit out of a tournament and you no longer "place" in that tournament unless you take start an official match and take a forfeit loss..
Ex Nolf and Kemmer in 2018.
Nolf reached the semis and med forfeited to 6th place, but took no losses. In order for Nolf to finish 6th, he must start and forfeit the matches he did not wrestle in. If he withdraws from the tournament, no placement points go to the team, only advancement and bonus earned up until that point. Bump up all lower placing wrestlers up 1 spot. Example the 7th place finisher now becomes the 6th place finisher including placement points, etc.
Also, get rid of the at large bids for NCAAs. You must outright qualify for NCAAs. This will discourage withdrawing from a conference tournament after reaching a placement round.
As for duals, not much you can do about it as coaches are capable of sending out a backup.