Layered PREFER_NODES not respected if mergeEdges and edges have labels

[keyserj]

Describe the bug
I sort my model by node type, so that nodes of a type are grouped together, like so:

However, if I add edge labels and set mergeEdges: true, model node order seems to be ignored. Here is an elklive to show the issue (hopefully link works, it seems like elklive was down so I ran it locally and just appended the compressedContent onto the live URL):

I recently learned that edge labels are treated like nodes during layout, and I wonder if this is related.

What I've tried:

• forceNodeModelOrder: true - works but I don't want to ignore crossing minimization
• crossingCounterNodeInfluence: 1 - theoretically seems like it should prioritize model order such that crossing minimization is ignored, same as forceNodeModelOrder (then I could try to tune to a smaller number), but it doesn't seem to fix the issue
• sorting edge model order in addition to nodes (still using PREFER_NODES) - works, seems like my best workaround for now, but PREFER_NODES seems like it's intended to function without caring about edge order

ELK Version
ELK snapshot/0.9.1

Additional context
Up until recently, I've ignored edge output from ELK, just drawing a simple bezier instead for each edge from source to target, and plopping the edge label on the midpoint. But there's a lot of edge/edge-label overlap, so I'm trying to include edge labels in the layout, and use the edge output to actually draw the lines/labels (hence my desire to also set mergeEdges: true).

[soerendomroes]

I think model order does just not work correctly with hyperedges. Any considerModelOrder strategy just sorts the ports and sometimes, the nodes. If however all edges have only one port, this does not work.

I will mark this as an improvement.