Q retreats and X sells the selected operator during prep, through the same buttons (never an item, never while typing in a field); the buttons show [Q] / [X]. Contributed by @SpiritedAwayCN.
Online co-op browser remake of Arknights' Stronghold Protocol: Alliance (client-simulated combat, official waves/bonds/items/strategies, 3D board, facing wheel, operator loadout, official emotes, deployment scripts).