Chest energy bar (separate and combined)

Each Kingdom level should give you a "base" number of chest you can open every minute and not only a type of chest. Right now, you get to open better chest tier after upgrading your kingdom, but you end up having to open more of the "lvl1" wood chest to get to the next kingdom upgrade

So each kingdom lvl should increase the "total chest" you can open per minute, not only the type/tier
You get a second "energy bar" that let you freely choose which chest you want to open, without any specific cooldown. Chest energy bar refill of 1 every 1 minute. So, as it stands, would be something like this, based on Kingdom level

Kingdom 1 - 1 resource chest and 1 armory = 2 chest per minute
Kingdom 2 - 1 resources and 1 armory = 2 chest per minute
Kingdom 3 - 2 resources and 2 armory = 4 chest per minute
Kingdom 4 - 3 resources and 2 armory = 5 chest per minute
Kingdom 5 - 4 resources and 3 armory = 7 chest per minute

That way, a kingdom 3 can choose not to open bronze chest if he is full of verdite but opt to open 4 wood chest to get only ember. If you think that this will be a bit too much boost of ember drop, you can just "split" the bar into the resources bar and the armory bar
Chest should still cost 0.05 normal energy and have that animation cooldown before being able to open the same one again (so this is not a batch chest for non vip players)