You do need to research factory upgrades for all of the goods, not just your boosted goods. In higher chapters, another set of goods is introduced and they are made in the same buildings called Sentient goods. The buildings don't show that yet in the production window, but where you now see the 1 and 2 day productions it will change to 3 and 9 hour productions for the new goods at level 24. Your boosted Sentient Goods are your current boost +1. So, if you're boosted in steel now, you'll be boosted in tree gum for Sentient goods and those will be made in a lvl 24+ planks factory.
Don't worry about building that factory now. It takes up too much space and it's Chapter 12 before they are introduced, so quite awhile before you need them. Most players wait until they're near the end of Chapter 11 and start building their Sentient goods boosted factory then. You'll still need your steel factories, too, though there will be reduced demand for them. Many players find they can replace 1 of their current boosted factories with the new Sentient boosted factory. You get back the space, population and culture when you take it out of your city and can use those resources towards the new factory.