No stacks, no timers, just all you can do hold clues.
They will still take up an inventory/bank space, so you'll still be limited on how many you can hold or bank. No fussing around with timers and having to re-drop every 55 minutes.
The only issue I can see is that clues with the same step but different step progression would stack in the bank, potentially. To remedy this, every step you do would progress all clues of that type and reset to 0 upon receiving a casket. If for example you were on a 5th step hard clue and you had 2 of the same dig spot, only the higher placed clue would complete as to not finish 2 clues at once.
Progressing multiple clues would allow for some strategy in doing steps efficiently by holding one that's in a remote location until you get another of the same or close-by step where you can do both or many from the same teleport.
Spam open implings, stay on task, keep mining/fishing/wcing, more raids/Skotizo, whatever. NoFoMo