I don't think you have to model all the hardware of the partitions. Usually, bathrooms are modeled with walls, doors, and the accessories such as paper dispensers, hand dryers, etc, but the hardware of partitions is usually shown in typical details. But, of course, that's up to you.
However, If you still want to do this with a line-based family, then spend some time making that family a little smarter, including parameters for gaps at both ends, so that you have maximum flexibility of adjusting the start and end point of the partition.
By the way, I don't see any "failure" of Autodesk in regards to the line-based family. It is what it is, a platform for something. It is not intended for any particular function such as drawing toilet partitions. It's the user who has to adapt the family for the function. If you see that the family has this behavior of joining endpoints, then put a gap in the family, put smart accessories in it, and problem solved.
Alfredo Medina _________________________________________________________________ ______
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