Chest key from battle

Overlapping is quite a problem on chest mechanic
Moonite is the first one having a "huge" boost since I can drop it from 3 different chest. All other above moonite are in the same situation.
Since the battle spin upgrade, higher kingdom lvl simply can skip the higher tier chest. Armory first (totally useless) and resources second (drop of moonite etc is huge, with only normal chest it took me 200 chest to get to 50 drakon, now I'm over 200 only with around 5/600 mobs killed, that gives me more XP, bronze and resources than keep on opening chest)
So, the problem is the overlapping, right now at kingdom 5 I can see drop of stormis drakon and voidium that I don't need at all. I need ember and verdite mostly.

So the idea is this. Instead of dropping the resources itself, give players "x" number of key, that they can use to open the chest they prefer to open. So if I got a resources jackpot from battle, I just got 200 key and I can choose whether I want to open 200 wood chest or 100 wood and 100 bronze chest.

Only things is, I will at least switch the odds with normal chest (that need to stay anyways, this doesn't have to remove the old chest thing). Having to wait 60s and spending energy and bronze should have 100% drop ratio, while the battle ones could have reduced drop ratio. Honestly I'll prefer them having 100 both since bronze is a huge bottleneck for f2p but also for those with lands (you have to choose tlrpg, resources or bronze) but also battle can take lot of time after some win streak
Furthermore, the chest with key should have at least a 5x batch opening (imagine having 1 jackpot, 4 huge and 10 medium in 50 battle, that way I will have more than 500 keys) and almost no cooldown, as the battle spin chest have
This chest will count 0.1 towards the guild chest count