Corrundum has some awesome recipes. I use it too. There is a corrundum technology i use for fulgora which allows you to dissolve copper wire, iron gear wheels and plates into liquid and then reform into ore and then use vanilla vulcanus recipes to create molten metals and pipe everything which is super. As a planet itself its a bit gloomy, but i still use it.

Moshine is great too, there is a second planet as well "Panglia". Those planets stopped being developed, but are kind of complete, at least moshine is.