Laying tongue and groove boards in the attic - tips

So, I have to start confronting the topic slowly. Rauspund has been lying in the attic since the shell construction. And I'm currently thinking about how to approach it properly.

Initially, it was planned to lay the Rauspund from gable to gable. Perpendicular over the (keel?-) beams of the roof truss (which you basically walk on and go from eaves to eaves).
However, this would mean the Rauspund would lie directly on/above the insulation placed between the beams, which is an issue because of air circulation.

Tips were already given ages ago to "raise" it. Now I thought, to avoid increasing the height with several (unnecessary) layers, instead of laying the Rauspund lengthwise, to lay battens lengthwise, that is from gable to gable. At what distance should the battens be placed from each other? And then rotate the Rauspund and lay it on the battens, in this case from eaves to eaves.
Now it still needs to be cut at the top, is it a problem if cutting residues, i.e., more like the fine dust that is generated when cutting, land on the insulation? Or how can this be prevented?

Thanks for feedback!

Yes, you can do it like that, 60cm distance, I just let sawdust fly around and then leave it lying there. Theoretically, you can also make a sawing area that you line with something beforehand.

Tips on how to "increase" that were given here ages ago.

What to increase: the structure or the air circulation? - internal sources, by the way, you are free to link here.

What to raise: the structure or the air circulation? - internal sources you may freely link here, by the way.

The structure. If I want to lay the rough plank lengthwise (from gable to gable), I would have to lay the battens lengthwise on the beams, then one crosswise, and then the rough plank lengthwise.

What height/width of the lathing would be sensible there? 3x5 (width/height) or wider? In case two joints of the tongue-and-groove planks rest on one lath to have sufficient bearing surface accordingly.

yes, I would do 4*6, that's a standard size. I only doubled it up and made 2.5x4 (laid flat on the beams) and if I imagine that I had one centimeter less for the floorboards, it would have been very tight.