I've been looking at automatic generation of standard cell libraries. Even if the cells generated are 20% worse than hand placement, I'm reasonably confident that the resulting netlist will still end up smaller due to gate fusion.

I presume it can't generate latches or other cyclic structures? One of the cells I'm missing in the standard library is the Muller C-element. While it seems you might be able to get it by abusing the 3-input majority gate, it would surely be more efficient with a direct cell.

Maybe I could give it a go?

if you can make a latch then you can make everything I believe