On Tchekor I'm swimming in calcite, ice and sulfur but lack a bit of coal for proper plastics production. (Sulfuric acid as the natural ressource is way more economic than ice and sulfur from recycling).

My suggestion would be
1. double coal and half the other's chance in the "Tchekor scrap recycling" recipe.
2. Making calcite a very scarce product (e.g. 1%, similar to holmium in vanilla) would enforce relying on the other recycling products more (inserters, splitters, rails, electric poles).

Done; this will be reflected in the next update though I'd like to test this again on the comfy server to see.. I thought I remember we had a lot of excess coal when we played.. but its been a bit.. I've moved 3% calcite (5% to 2%) and 2% Tungsten ore (8% to 6%), and 3% ice (12% to 9%).. 8% total into coal (8% to 16%).