the Piston_extension block (block 36 from now on) creates a ton of fps lag when being ticked by the client.

1.7 Behaviour:
this block on 1.7 used to be a transparent block, and you could pass thru it, you could see the hitbox, you could not brake it, and on right click it dissapeared.
lag-wise it was just normal.

1.8 Behaviour:
in 1.8 this block is totally invisible,you dont see the hitbox, you can pass thru, but it prevents you from placing blocks where it is(Really userfull behaviour in my opinion), but the fps's drop ALOT if you have some thousands of them.
i drop from ~650-700 fps's on a empty world to ~80-100 fps's with 1681 blocks (41x1x41 area) this is a huge drop, specially if you are using them to define the borders of a map, witch you want ppl to be able to fall off the edge, and you dont want them to place blocks against the border, but you dont want them to place blocks outside, but this requiere some hundreds of blocks if it's a big area.
this makes my map go from 300-350 fps's to 30-50 fps's, but just using optifine makes it go to 400 fps's in both maps with and without block 36

please remove the clientisde ticking of the piston extension, bcos in an old map of mine i had tenths of thousands of blocks (1.7) when they did not lag, and opening it on 1.8 made my client 1-2 fps's and usually crashed and gave the error "clientisde chunk ticking took <huge number> ticks, considering it crashed" or something like that