Vinyl: Only glue on underfloor heating?

I can hardly explain how a 1 mm thick glued layer appears to be of higher quality than a 9 mm floor with a corresponding HDF layer, etc. pp.

Sure. After all, the glued layer does not flex and is very close to the feel of walking on a solid floor. With click-lock coverings, I almost always notice this springy effect.

Whether this would be the case without underfloor heating, I unfortunately do not know.

What are Bio floors?
The build height of the vinyl floors we compared was consistently 5-6mm, whether glued or clicked.

Bio floors are free of any plasticizers and harmful substances.

For example, Wineo 1000 (also available as multilayer), Haro Disano, and also Parador Eco Balance Pur; the Meister DD 300 is also said to be suitable in this regard.

Bioboden are free from any plasticizers and harmful substances.

And are the disadvantages of these floors, compared to conventional vinyl floors, exclusively the prices?

Whether that would be the case with a missing underfloor heating, I unfortunately do not know.

Ok, the vibrating sounds logical, it probably also depends a bit on the quality.

But, what should that be in the case of no underfloor heating?

With conventional heating, you can use any floor. Go to the specialist store, they always have sample areas, walk on them and decide. Everything works. Karsten

But, what is that supposed to be without underfloor heating?

Well, in an old building without underfloor heating and possibly on the ground floor with an old "cold" basement, a directly glued floor might not be the best choice; a version with insulation would actually be better.
Furthermore, a floating floor is more forgiving with uneven subfloors.

But in a new building with underfloor heating, firmly glued coverings are far ahead.