I find it easier to just create a box from the line category, but as soon as I master where I want my box, I get these position errors, similar in Finale. Dorico should fix this to create a box template:
There are some experts here on creating Aleatory boxes, hopefully one will chip in.
From my limited understanding, I think you need only horizontal lines with end hooks, and you adjust the length of the end hooks to create the sides’ of the box.
