Phương án lớp top cho Multiboard beam (Multiboard beam top layer alternative)

Someone on reddit asked why there was not much holding together the top of a multiboard container made with beams. I've used beams on top instead of just the corner pieces before, but why sacrifice space on that top opening.

Lacking most of the design elements of the genuine beams, these are made for a very specific size, I'm too stupid to parametric.

Suggest lite clips in the end of the long bars, full clips might split the layers.

I thought 0.2mm gap on the end of the long bars would be a good idea, the gap came out to 1mm on mine so dropped that to 0 and uploaded.

I can generate some other sizes if there's one you'd like.