Keeper League Rules Question?

My league is in the middle of finishing our keeper league rules and wanted to see what everyone thought. We’re having trouble on deciding what to give up for the keepers though which is why I’m turning to the footclan.

So far:

3 keepers max-3 different positions

Only 1 keeper per round based on ADP i.e. can’t keep Cook and McCaffrey if they are both first round ADP for the 2020 season.
Previous Season draft position is irrelevant because of this.

Now to what we’re having trouble with. If you keep a player whose ADP is in the first round, then would you lose a first round pick? The other option we have is to lose a round down, so keeping a first round ADP would lose a second round.

What are your guys’ rules and experience with Keepers?