Crafting and building are not the same thing. They are two separate features with two separate mechanics and in-game tools. 
- Building refers to making structures.
- Crafting refers to making items.
Both would likely require their own separate option, as with other customisations for similar games.
In the meantime, while @MrAntiFun considers your suggestion, you could try using console commands alongside the trainer: Subnautica - Console Command Cheats at WeMod/Wand.