I have worked on many Generac diesels and once the garbage is corrected like harnesses fill tubes regulators their reliability improves markedly.
Onan had industry-leading failures with the remote start harness at the generator. Onan use genuine MOLEX gold plated MOLEX connectors? Hell no. They saved four dollars by using a nineteen cent play-toy plastic connector.
Thirty years ago I took a full carton of MOLEX threaded connectors to Mexico and made a fortune visiting remote beaches. I ran out of them by the time I reached Puerto Vallarta. The metal connectors looked so impressive they sold themselves. One beach north of Mazatlan I installed twelve of them. Smart RV'ers listened to tales of woe from others and I converted a dozen before they could fail. So it just isn't generac.
Now the big failure is slide out switches. I have 24 75-amp rated motor reversing switches.