@User Of course a ballpark number is better than nothing if you know that is what you are using and that's all you can get derived from the layer stack-up. The TSMC qualified flows I have seen did not use these values from the technology LEF file; are rad hard libraries were released with test LEF file without those number in them. If I remember TSMC even provides capacitance tables specifically for Cadence Encounter and other tools in their qualified flow. And for final (timing) sign-off then Calibre is used as golden tool.