Lag efficient wool farm

An engineering video rather than a build guide, by Jetmaymendo, inspired by ilmango's cat gift farm and his efficient wool farm. Sheep are sealed individually inside glass with only their heads exposed, observers watch the grass they eat, and dispensers shear them from above. The trick that makes it dense is that items dropped by a mob always spawn at the mob's eye level, so the wool elevates itself up through stacked modules and one water stream at the top collects the lot. No hopper per sheep, which is where every other wool farm spends its lag budget. Nearly a third of the video is theory, and there is no block by block section.

Do not put sheep in as babies. AlexaRawr says they end up badly positioned once grown and some of them never get sheared.
Getting the sheep in is the worst part of the build and there is no clean method. Jetmaymendo drops them in through holes in the glass layer from above, then pushes the glass back with pistons section by section, and says it took forever.
sixessful spotted that the observer sitting between the two grass detectors never fires. Jetmaymendo tested it and agrees, so it can be swapped for another grass block and gain a little rate.
The honey blocks are not decorative. Items were glitching inside ordinary blocks, and honey or chests fix it.
Shroomlights can be swapped for jack o lanterns but not glowstone, because the block has to be powerable. Any powerable full block works if you light the area some other way.
You do not need a crafting table for the shears. Three commenters point this out and catrisit mass crafts them in the personal crafting grid and drops them over open barrels with Q.