Assembly currently uses a blacklist of blocks that are usually naturally generated. While this solution is good enough, it can lead to some jankiness when a player tries to incorporate a natural block into their build. Often a player might include stone or netherrack in their build, for example. In VS1, this issue was particularly present in that a ship may have accumulated a snow layer, but that snow layer was left behind if the ship was disassembled then reassembled.

Potential solutions:

• Keeping track of all naturally generated blocks. Spigot plugins usually do this by keeping a separate database of all blocks generated in the world, rather than setting it as block metadata.
• Keeping track of all player placed blocks. This may prove incompatible with mods like Building Wand style mods that add other ways to place blocks.