ᐅ Help… What type of insulation should be used under a screed? New construction

Hello,
I’m trying to figure out the correct insulation to use under my screed.

The intended setup is as follows:
Concrete slab,
Bituminous membrane,
5cm EPS DEO 150 kPa (2 inches),
5cm EPS impact sound insulation (50-2) 10 kN (2 inches),
Plastic sheet,
Underfloor heating and cement screed,
Tiles.

Now, while laying it out, I noticed that the impact sound insulation is quite soft.
Also, I’ve read online that the screed can settle over time.

Is there a risk that this could cause the tiles to crack?

Would it maybe be more sensible on the ground floor to omit the impact sound insulation entirely and use two layers of 5cm EPS DEO 150 kPa (2 inches) instead?

Oh, and one more thing, the current impact sound insulation has a dynamic stiffness of 30.

My new build does not have a basement.
Do I even need impact sound insulation on the ground floor in that case?

Thank you very much!

Hello,

can’t anyone say anything about this???

THANK YOU