DC penalties are not what DbD needs right now
The game is in such a poor technical state for both bugs and issues with the dedicated servers (hey there hit boxes), and in a poor state balance wise with some things being so under powered and somethings being super over powered, DC penalties don't make any sense.
First ask, why do people DC. Well you might think out of rage for something but I think most of the time when someone rage quits it is not something another player did, it is something *the game* did to them.
So to cut to the chase and avoid a super long post. Instead of adding punishments for DCing actually fix the things causing people to DC.
Can they fix them all, probably not. But there are a good few that could definitely be fixed within a week.
Like disabling Ormond and Haddonfield until the map team can get around to reworking those into playable maps.