Mixing blocks (And this means mixed slabs)

I recently discovered a new glitch/bug in minecraft. As some of you might know, block 36, a very little used bloock, is an invisible block that entities can pass through. Also known as the piston extension block, this block comes with many bugs. Previously, it was used by mapmakers as a click detection block. This no longer works as of 1.8. One of the bugs that comes with it is freezing falling blocks (sand, gravel, etc.). If you freeze one of those blocks, it becomes a ghost block, allowing entities to pass through it. This may already be a useful concept for mapmakers. I decided to take it further and play around with the block more. I tried to make a Lens of Truth concept with this block by replacing the block with glass, and vice versa. It did replace with glass, but not the other way around. You can do some additional testing with this, if you'd like. Now, here's the cool part, as many of you may have already guessed. If you spawn falling stone (for example), it would freeze the stone like a sand block would. I reccomend using transparent blocks for this, as opaque blocks (diamond blocks, as an example) will just look glitchy. The effect of this looks similar to the pictures above.

Update: This makes the long-awaited feature possible. You can finally combine 2 slabs together. This makes it so maps are able to have much more detail put into them.