ᐅ Renovation – Subfloor Construction for Tiling! Looking for Tips and Advice

Hello fellow homebuilders,

I am currently planning to completely renovate a room, and the floor is giving me some trouble because it will be tiled later. Of course, cost is also a factor.
I have come up with three options, with the last one being my favorite, but I’m wondering if 20mm (0.8 inches) is sufficient and if tiles can be laid on it without additional preparation.

Layer structure always from bottom to top

#1
Concrete slab
30mm (1.2 inches) EPS insulation
20mm (0.8 inches) OSB
Primer for OSB
Fiber reinforcement on OSB
10mm (0.4 inches) tile + tile adhesive

#2
Concrete slab
30mm (1.2 inches) EPS
20mm (0.8 inches) Fermacell dry screed
10mm (0.4 inches) tile + tile adhesive

#3
Concrete slab
50mm (2 inches) thermal insulation screed composite (Does something like this exist?)
10mm (0.4 inches) tile + tile adhesive

#4
Concrete slab
30mm (1.2 inches) EPS
20mm (0.8 inches) composite screed / floor leveling compound
10mm (0.4 inches) tile + tile adhesive
For the last one, the question is whether 20mm (0.8 inches) is enough.
Any other suggestions are welcome!
The total build-up can’t exceed 60mm (2.4 inches) because I am limited by the height of the other rooms.

Unfortunately, it’s always a bit of a compromise in an older building 🙁