SavedData-backed storeRight-clicking a piston cycles how far it pushes, and there is nothing to find: no recipe, no item, no particle. The block looks identical at every setting, so the only way anyone learns this is being told.
With village-quests installed, a mason or toolsmith wants a gate that actually opens and asks you to set a piston to a reach of three. One is what a piston already does and two could be an accident; three is unmistakably somebody who knows.
With block-tip installed, looking at a piston set to 2 or 3 shows "Pushes 2" or "Pushes 3". A piston at 1 shows nothing, since that is what every piston does.
Both are optional and guarded: without them the mod behaves exactly as before.
Piston Extension runs server-side, and Pandorical is required: the server will not load this mod without it. The Piston Shaft is registered as a Pandorical content block and its assets are synced from this jar.
Clients are the optional half. A player on a Pandorical client sees the shaft; because it is a real registered block, a vanilla client cannot render it and cannot receive chunks containing one. Extension length, sticky behaviour and the push rules are all server-side and unaffected.