Hmm it should be possible, but i've never tried to set it up.
Here's a comment about setting up constraints: https://github.com/mxgmn/WaveF...
I think the trick is to figure out the index of the desired tile, then in the wave array set that index to true and the rest to false for the desired tile. I also think the "while(Propagate())" has to be done before calling "Run(seed, limit)" to finish the output
from the unity component, you can access the underlying model ( SimpleTiledWFC.model ), which will have the "wave" array and "Propagate" method
Oh, also i think setting up manual constraints would have to happen between these lines: