Thermal balancing of underfloor heating - How to proceed?

Attached are the pictures of the distribution box.
If I turn the Taccos all the way up, the hydraulic balancing is completely overridden. Wouldn't it be more sensible to regulate based on the values?

No, definitely not, you'll drive the entire hydraulics into the wall.

Just a question, does it matter if the tubes are at the top or bottom in the HKV?

No, that is irrelevant. It also works perfectly fine without it.

As said: note everything down meticulously to be able to take a few steps back if needed. However, it will obviously be difficult to get everything under control anyway. If I interpret the numbers correctly, the [Leitungslängen] are recorded there. Adjusting that will probably be a masterpiece.

That's why I say it. Under no circumstances twist wildly. The system is now most likely more or less in equilibrium. Therefore, only minimal adjustments are necessary, if any.