I don't think it is worth it. There is only one Ludus and it only exists in 5p. Going for the Ludus solely is risky and not worth losing an arms race. I think it makes a great card to hide aswell if you opted out of military. Lighthouse on the other hand. Well, why not go for both red and yellow? I have made some of my best scores doing both at the same time and finishing with lighthouse and Ludus, you'll score high. Buffing lighthouse would make yellow too desirable and probably op since there is a limited supply of yellow cards compared to Brown in resource play, for an example.
Sure Ludus makes red appealing but that is the exact point. In old version people don't want to build military because it didn't score enough in 5 or more players compared price so technically you were supposed to avoid playing red. One thing here is committing to a strategy. More and more advanced the play is, the more It is sticking to an even complicated strategies while disrupting others. Dumping cards on purpose was probably unheard of when the game was initially released but has since become a standard play in certain situations. More ways to win, better for the game. Ludus can save a game for someone who lost all other opportunities than red. Bonus, it encourages strategy that tries both green and red, Malung this potentially the highest scoring combination, if succesful. One of my games i saw a player score 89 on combining red and green.