While this mod is still WIP, I see a lot of potential, it will be great once it's complete.
What about rubber? I can see some good uses for it, like cables, belts (rubber sheets), inserters (rubber belts) and pipes (rubber sealants).

Keep up the good work, "We will watch your progress with great interest, young Skywalker".

Thanks for your comment!
I will introduce synthetic rubber (styrene-butadiene) down the line in the next patch, which will be used for express belts and some applications that requires liquid-tight sealing. I am also planning for tiered different alternatives (e.g. silicone rubber) to introduce in different stages of the game.
If you have any opinions or other suggestions, feel free to tell me here, or better if you find me on Discord!