It is currently possible to legally compound small blocks in the vanilla game, by using various techniques meant to 'trick' the game that a block is being placed on a new grid instead of the existing one. This causes a collision criteria being used for placement rather than the positions one and allows for blocks to be compounded with reasonable rules and no real exploit possibility.

It would be great to for be able to switch between these two criteria (maybe shift key, like large block compounding?) and place blocks like this directly, just as a measure of saving time as well as popularising the feature (which currently has to be often explained to people and isn't very intuitive to use in the beginning).

An further possible expansion to this could be a customizable value of how much of the collisions' volumes could overlap, f.e. 10%, 20%. This could allow for certain servers to give designers more freedom, while still making this feature safe from any potential exploits and misuses.