Also bio-plastic from trees is a trap. Don't go for it!
You need 1 swamp tree for one plastic producer, they are limited like swamp gardens, but there is no handy tech to get more with a 5% chance, not at the stage where you need the first plastic.
Also, I'm in a desert bordering on temperate areas. I drove around for more than 1h trying to find a single swamp tree. My map setting allow for this but forget about it with bitter expansion or a death world.
Next, I'll try plastic from plants...