I am attempting to Tune a resistor to change the Operating point analysis, but it does not work. I can select a resistor, but it does not get added to the “tune” things. I do not do much (or know much) about simulation (yet) but I have tuned some resistors before in the transient simulation. I am guessing that tuning values for the DC operating point is simply not implemented.
Is this correct?
That’s correct. See Simulation examples for KiCad8/Eeschema/ngspice for a transient sim example.
It turns out that just adding a DC analysis already enables the tuning thing.
A few days ago I was having a lot of trouble with the transient analysis. Not because of ngSpice, but because my circuit was not stable, and because of that the ngSpice analysis was also getting very slow. And therefore I put the transient analyses on hold for a while and focused on the DC operating point first. But with a capacitor in the right place it’s getting stable now and the transient analyses is both stable and very much faster.