They actually moved some of the base game content from the starting planet to other planets with the DLC. And you can transport things between planets to kick start your factory, so each new planet should take significantly less time than the starting planet. So it’s not really as long as playing through the whole base game then 4x more.

Still takes longer to beat but not like 5x. Closer to 2x for most people I think. Don’t be afraid. The interplanetary factory must grow.