Inspired by Erna Janine and Saori weavers who use reedless weaving, I tried it out too.
Reed is used to determine the warp density and beat down the weft. So in reedless weaving I separated those functions
1) built "weft mover": a metal "comb"  (drilled 2mm holes through aluminium tube and inserted nails through the holes)
2) Grasshoppers. I built 5-cm long metal combs to push warp apart where needed, to make warp lines move like with RailReed but even with more freedom. The logic of this is little device is that you insert it between warps under angle and then turn it parallel to weft (thus the warps move wider apart) and fix the position. 
With first experiments I fixed the new position with long legs, so it reminded me of grasshoppers. Long legs to fix the position to the lock (just a heavy metal stick) are better than short, then I can see the change at once.
Nexts wefts secure the position of wefts and then I removed the grasshoppers to the new position. The photo shows how grasshoppers changed the warp lines.


The sample after washing. The warp lines keep the deformation.  Merino (black) and heavier woollen (white) warp and UpYarn carpet yarn.
Next I will experiment with different fixing system for the grasshoppers, but proof of concept is here, isn't it?