Thank you both.
Very interesting info Bo. I had noticed the wires were stranded on the closeups of a VTAL D-V. So, the drag wires are then most certainly thicker than flying ones, and probably close to a 1cm diameter. My 0.12mm nylon thread should be OK at 1/72. Flying wires are too thick, but fortunately they are in the shadow of the upperwing most of the times, which makes them appear a little thinner.
Yes Antonio the new method I want to try looks a bit like what you did on your model, the main point being to have thinner tubes for turnbuckles. I was thinking about using buckles from an Eduard PE sheet but the inner diameter of the hole is inferior to 0.10mm, which would be too small. So for the time being, the only thing to do is building buckles the way you did.