A4 is indeed signposted as a toll road ('płatna') between juctions S1 Brzęczkowice and S52 Balice I. However, the flat fee is paid only when passing through the toll booths, of which there are two: one between juction Brzęczkowice and junction Jeleń, the other between junctions Rudno and Balice I. If one doesn't pass through a toll booth (by entering and/or exiting the motorway on one of the junctions in between the toll booths), they do not pay.

Thus, despite the entire A4 section being signposted as a toll road, driving between junctions Rudno and Byczyna is de facto free and should be marked as such for OSM, giving users who want to avoid paying the option to route on A4's unpaid section.

I hope this explains it well. I'll go ahead and close this note as nfar.