@User: The slowness is all in the startup. . . ngspice has a bizarre way of reading all of the files in the lib.spice file even when only one corner can be specified. But make sure you are copying the file

/usr/share/pdk/sky130A/libs.tech/ngspice/spinit

to your simulation directory and rename it

.spiceinit

or else ngspice will run really slowly. Otherwise, if the "normal" slow reading of .lib.spice bothers you, you can make a local copy of it for yourself and remove all the sections for all the corners except for the one or ones you want to simulate, and ngspice will start up much faster.

ah, I see, thank you! I will make a copy of both files then