@Joshua Smith: Welcome! My main outstanding issue with Xyce and sky130 is that sky130 has diode level 3 models which ngspice has some kind of an implementation for that seems to work (see the discussion above that I had with Eric starting March 22). Also: I had a wish-list item for a digital LUT cell (see the discussion above that I had with Eric starting April 27) that matches what I implemented in ngspice and is what I use to make a direct translation of any standard cell set of any process from transistor level to digital gate level. ngspice uses "xspice" (code in spice3 contributed by Georgia Tech, if I recall correctly) which is a complete event-driven simulator that exists alongside SPICE; xyce's digital gate simulation is very different but with the LUT cell, it would be more or less equivalent to what I can do with xspice in ngspice.