If you're looking for more novelty, there are a lot of mods that add cool new complexities.
I like the Seablock pack - the core premise is that you crash land on a water world, and need to extract all your resources from water. The production loops are much more complicated (you start having to deal with byproduct management just an hour or two in), but in return there's almost no enemy time pressure. It also includes some ingame recipe-planner mods, so it's easier to plan-then-build.
The core gameplay loop is still very much the same. More complex recipe is not really a more complex game. It just means more of the same planning and calculation but with more variables - which is to say more tedium not more fun.
I like the Seablock pack - the core premise is that you crash land on a water world, and need to extract all your resources from water. The production loops are much more complicated (you start having to deal with byproduct management just an hour or two in), but in return there's almost no enemy time pressure. It also includes some ingame recipe-planner mods, so it's easier to plan-then-build.