I had a question regarding the ecoroof modelling. Does the ecoroof in EnergyPlus consider freezing conditions on plants and soil?

Additionally, it is mentioned in the engineering reference of ecoroof that, "The ability to track moisture-dependent thermal properties is not implemented yet due to stability issues in the Conduction Transfer Function (CTF) scheme". However, in the code for the ecoroof modelling (https://github.com/NREL/EnergyPlus/bl...), it shows the thermal properties are updated based on the moisture content in the soil. I'm having difficulty understanding and I'm a bit confused about what it means by not being tracked due to stability issues.

Could anyway please help me? I would really appreciate it.

Thanks, Bita