Option to opt out of war

We want to allow clanmates to sit out a war if they're going to be otherwise indisposed and won't be able to use both attacks. We also want the ability to vet new clanmates for dedication and activeness before allowing them to join our wars. It would be very beneficial for Supercell to add a toggle switch/check box next to each player's name in the clan list so that players can mark themselves out of wars if they choose. Leaders could have the ability to make this mark as well.

Right now the best option we have is to send clan mail asking guys to let us know if they're out, hope that we catch their response in chat, manually keep a list, kick guys out before war search and invite them back. Having a one-click opt out option for war would simplify this process tremendously.