Comment by mynameisnoone

Use a different sediment pre filter that those cheap-o ones. It's just to prevent fouling of the rest of the system should serious sediment or scale come down the pipe.

For a final filter, it's a good idea to use a specialized filter for chemicals of concern, typically heavy metals and/or chloramines. (Example: https://matrikx.com )

NSF polypropylene should be studied more but I doubt it is a significant source of microplastics. Although, I wished pressurized residential RO systems could be 99% stainless steel or something else inert and easy to clean like thick borosilicate glass because PP does stain. It's important to use NSF listed / FDA compliant (CFR21.177.2600 A-E) O-rings and lubrication rather than random junk from Amazon. Any "water filtration" system that doesn't use RO or significant water pressure is only for taste and not a filtration system.