Just solved it. Hurray a time machine
undo-redo_block.capx
warning: no array get involved
Undo-redo feature is common mechanic in various puzzle game. The example showing how block movement can be undo or redo. The concept is very simple; Each time player drag the block to a new position, the information are stored into dedicated separate text object by append x and y value.
When the player need to cancel or recall last position, the system just need to iterate using tokenat. Even the system updated in the middle of interfere. I had this solution around my head, but just actuate it just now.