Inspired by ImpulseSV and BdoubleO100 janky redstone on Hermitcraft making an armorstand queue for Decked Out 2, I had this idea for a more reliable version. Right click the noteblock once to advance the armorstands forward and bring the first one to the back of the line. The observers flash the gates open so the armorstands can be pushed along by the water one spot.
Simple enough to recreate from screenshots here. Last one details the tricky water setup beneath. You can cover the redstone with carpet if so desired.
by abros_vii