[Ideas] Level 15 clan castle perk: 5 minute donation cooldown?

I know this has definitely been asked, and I understand that the clash of clans developer team doesn’t want to add clan perks beyond level 10 because it will disincentivize people making new clans. But could we please have a perk at level 15 where the donation timer is reduced to 5 minutes.

I have noticed that when I activate a training potion and do my legend league attacks, I am always waiting for the timer to ask for clan castle troops while my queued army is already done and all my heroes are awake.

Clan experience required to reach level 10 is 34,000 and then from there to reach level 15 you would need an extra 54,300 experience (more than double) I’m not looking for a competitive edge, but just some incentive for older clans to continue to grind out wars would be much appreciated.