Template:ParallelAsynchronousThreadBlock
Word Tearing and Any Falling Block via Asynchronous Threads
From 14w32a (1.8 snapshot) to 17w46a (1.13 snapshot), asynchronous block updates allow for block palette corruption, and this corruption, when combined with the registry palette type, can allow for the creation of any block that can exist, such as {{{1}}}. Asynchronous block updates also allow for usage of the "generic method" to create a falling block entity of any existing block in your world.
These falling blocks may also be used to obtain their respective item, if it exists in item form, such as end portal frames. Blocks such as end gateways cannot be obtained as items with this method, as they have no corresponding item. Falling blocks also allow for the placement of both blocks that cannot normally be placed, either due to operator restrictions (e.g. command blocks) or not having an item form (e.g. end gateways).