Edge insulation strip, from the floor slab or the last insulation layer?

Hello, I am a bit confused because there are different statements on the internet, and the answers from contacts are also unsatisfactory. For us, 7cm EPS and 2cm impact sound insulation come on the floor slab (after that underfloor heating/screed/tiles). On the internet, it says that the edge insulation strip should only be installed at the last insulation level, so in my case after the 7cm EPS have been laid, but there are also descriptions where it is stapled from the concrete slab? Would it be wrong to lay EPS first, then the edge insulation strip, and finally the impact sound insulation? Regards

The edge insulation strip sits on the "Tackerbahn" of the underfloor heating. It makes no sense underneath, as it is generally not high enough there.

OPEN? so that I understand you correctly, if it is like in the picture, it is wrong? that's how I would have done it

Insulation, floor heating carrier and then glue the edge insulation strips on it.

Just as shown in the sketch is correct, otherwise the screed will run against the wall with slight settling.

So there are also different opinions here again, I will now do it as shown in the sketch. Material is ordered, and it will take a while until I get something else.