As of Relase 2013-10-16 - Arcade Redux Phase 1 players can not deposit minerals to Gates, which have been their main reason to be in game. This resulted in four things:
1. Moonstone and Valestone are now obsolete.
2. Achievements got broken.
3. Minerals are obsolete for players not interesed in Battle Sprites/have them maxed. For some reasons some of them just want to sell materials alone.
4. Some players not interesed in BS/that have them maxed often don't collect minerals, even if other party members want them. This results in senseless arguing.

Why not fix it in most simple way? Three Rings can just add NPC that "manages arcade construction" in backstory and buys minerals to do this (for 2-4 crowns each. For me price could be chosen randomly every week). This will fix the issues above, make players happy (especially achievement hunters) and Three Rings will not lost anything on it.