There actually was no whitelist, but I just implemented it.
I've also installed a plugin that will register if someone is AFK for more than 2 minutes. If so, they will be ignored when it comes to players being in bed. So the active players can use the bed and sleep as normal while the inactive players don't have to be kicked. I hope this works as advertised, but let me know if it doesn't.
Also there is some downtime planned on Monday 6th of june for some server maintenance by the host. This downtime will, in the worst case, last from 2PM to 5PM but is expected to be much shorter if at all.