Question about `STD_DEVIATION_THICKNESS` in quad module metrology

There is unfortunately still an inconsistency between the quad module metrology. The key STD_DEVIATION_THICKNESS is required to be an array in the PDB test. See here: https://itkpd-test.unicorncollege.cz/testTypeView?id=627a356dba163f000ab63233. If we give this key to mqat, a single value is calculated and consequently the PDB sync fails. Instead of fixing again mqat to make it compliant with the PDB test I would like to ask if it makes sense to require that the key STD_DEVIATION_THICKNESS is an array? We measure only a single value per FE chip anyhow, so maybe it is better to change the PDB test such that this key is only a float. In addition, there is HICKNESS_VARIATION_PICKUP_AREA which is more meaningful to me anyhow.

For now, it is fine to just not give the key STD_DEVIATION_THICKNESS to LDB (it is not required) and PDB sync works fine. But maybe we can converge here for a nice solution :)