Not at present, no. If I add it in the future it will be in an example map and not as a general feature of the entire toolkit. The thing is that adding multi-tile units is not terribly difficult in itself, but it becomes increasingly complicated depending on how many other features I need it to work together with.
For instance, adding one new type of unit that is 2*2 tiles on a square grid that can only be controlled by the AI is the simplest take. If I want it as a generic feature I would want to add multi-tile units of arbitrary size for both hexagonal and square grids that work on multi-level grids and can be controlled by the player in a way that makes sense in how tiles in move range are displayed for units of any size. I have experimented with this quite a lot, and any solution I can think of that solves all of these problems becomes extremely convoluted and inefficient. It is a lot better to tailor the solution to whatever game is being made, which is why I will add it as a feature of an example map when I add it.