Here is an ultra compact version I tested. I set the openscad file to standard library size braille which works well, but a couple of easily avoidable issues arose. Firstly I set the tolerance too low. I thought 0.2 mm would be fine for my printer, but the pieces fit too tight. Secondly I made the depth for the tiles too low and they become too fiddly. I would recommend to anyone making these that they print a 2 cell wide test print with at least a 3mm cell thickness, and share there findings for others to get the best results.