@User We are not quite there yet, but eventually we will need this: Do you have a recipe for handling black-boxed structures (like RF MOSFET) in the extraction flow? And how to add the models later into the netlist (I guess just including the proper models?).

Yes, I do. It needs to be hacked into open_pdks. For any cell whose contents are a single device but which cannot extract as the intended device (which includes RF FETs and vertical parallel plate capacitors), you can force the extraction to treat the cell as a black box by adding the property

"device"

to the cell, with a value string that exactly matches how the device should appear in the .ext file. This will only work correctly if the cell is labeled with ports. The method assumes that all parasitics in the cell are modeled in the device.

Sounds promising. Where's a will @User there‘s a way 😀