Beam joints for gridshell

I'm trying to model a wooden gridshell in the form of a hypar and have some problems verifying that the rotations between connections are effectively released. It's the first time I'm trying to use the beam-joints command. To simplify the problem I made a simpler structure: a grid, simply supported on four points, two of which are elevated. Continuous beams are supposed to run from one end to the other. At each point where they cross, XYZ translational should be fixed, but rotation between crossing beams should be free.

I've tried a bunch of different approaches but none seem to give me a satisfactory result, or I am unsure that they are doing what I hope to achieve:

1) Simply release XYZ rotation seems to induce a joint also within my straight element (around the local Y-axis)

2) Releasing Rx and Rz, and assigning a low spring value seems to do the trick. I'm unsure though if my perpendicular beams can still rotate in all directions respective to one another.

I've also tried a bunch of other options and played around with the normal modes visualizer, but have the feeling I'm only getting more confused. Any advice would be warmly appreciated.

Tim