I'm sure many have tried but it sounds pretty hard. E.g. optimising for less LOC will lead to horrific code golfing. In reality you need a very complicated optimisation objective that trades off all those factors, I'm not surprised it hasn't been solved.

My experience up to now is that the models can do both "less LOC" and "clean code" at the same time, you just have to keep reminding it to them.

So the capabilities are definitively there.