Has anyone considered that it may not be a moderation issue, but a developer issue? 4chan doesn't have many, if even more than one, dedicated developers.
Bug fixes in whatever textboard software would fall on the blue palm tree man, along with making the textboard software compatible with 4chan's current moderation tools, and, presumably, porting the inline extension to the textboards. Plus, making the textboards compatible with 4chan's public api.
All that for the two people who would actually use the textboards.