In response to a request, I have designed a connection for the rookery tool head to be mounted on an MGN12C linear guideway.
Unfortunately, I can't test the design because I don't have an MGN12C lying around at the moment, but according to CAD there shouldn't be any problems.
However, it could be that you have to install the heatsink with a little more distance to avoid a collision between the hot end and the “Hot_End_Key”.
Many thanks to Gulsifer for sharing the Rookery design!
Updates:
2023-08-15
The author remixed this model.