ᐅ Subfloor Construction Without Screed for Solid Wood Planks – Experiences

My current plan is to have a standard concrete slab under the house; additional insulation is still possible.
Based on my experience with a house that has a basement, I had planned to lay a membrane on the raw subfloor (this time without a basement) as a moisture barrier. On top of that, I would install a joist or cross beam structure with loose-fill insulation in between (cork, perlite, hemp-light clay loose-fill; this is also what the contractor recommended).
I recently consulted a specialist company for these types of insulation materials, and they raised some concerns that the membrane on the raw subfloor might prevent moisture—potentially settling from indoor air in the worst case, through the wooden floorboards and insulation—from properly draining downward because of the membrane.
Their advice was to lay the joists directly on the membrane to protect the wood from direct contact with concrete and moisture, and to place the insulation directly on the raw subfloor instead.
In my opinion, however, this approach might carry the risk that residual moisture could rise from below into the insulation area, just reversing the problem.
One possible solution could be to use foam glass gravel when the concrete slab is first poured; however, I am not sure if my general contractor will implement this or if it actually makes sense.
I thought I had this issue figured out, but since there is no basement under the living areas in this build, it is making me reconsider. Ultimately, I want to avoid screed specifically because of moisture concerns.
Does anyone have more detailed experience or knowledge about this?
@Steffi33, you have a construction like this; could you share your exact setup (membrane, insulation, etc.)? Do you have a basement? What type of concrete slab do you have? What joist height did you use? Sorry for all the questions.