So, I know a few Yosys users follow me. I want to measure user awareness of Yosys synthesis options. If people like @oe1cxw and @ico_TC retweeted it, it'd be nice.

Timing-driven synthesis (through -abc9 options to synth_* scripts)

Register retiming (through -retime options to synth_* scripts)

Module-level synthesis [e.g. to see per-module stats] (through -noflatten options to synth_* scripts)

Disabling wide LUTs to reduce area (through -nowidelut options to synth_* scripts)

While we're here, how would you rate the overall synthesis quality of Yosys?