I make the display this long to test the limit. The original is 4 digits long, so it indefinitely stackable and I don't care to test it farther. There is a 15 ticks delay between each entry. My display use the signal length detection, you shouldn't have see something like that. It take 2 tick to display. But it take 1 to 10 tick to read the signal. It posses a reset function made the button a lever because it take 21 tick to put the system in position one, the stone button is fine up to 9 digits. So toggle the switch for 2 sec to clear the number and test it yourself. I have made a schematic for the original.