Here's a suggestion that I thought would be interesting.
Empty mist tanks, that can either be found from the end of level slots, or purchaseable from a merchant for a high crown price.
These empty mist tanks can be filled with only 100 mist energy at a time, and only if you have it in your current mist bar. The tank can then be saved for later and used whenever you choose to. The mist tank will then break, and cannot be used again.
A short simple suggestion.
"or purchaseable from a merchant for a high crown price."
Purchasable from vendor at a high crown price? then why not just use the money to buy energy from market.
I mean a tank that will always waste some energy-unless you can time it prefectly so you fill it when you have 0 mist- vs raw uncapped energy.
This has been suggested like every day since spiral knights is out, we already can purchase crystal energy, OOO makes money out of ce and why would they reward us for doing nothing? The system works just right, a little difficult for us but pretty fine for them.
when you don't have time to play go on keep the energy for another day kinda gets rid of ce i guess besides the crafting purposes of it.