yes they do, breaking the raised edges off the crosshatching happens almost instantly on startup when the motor comes up to temp. typically a proper breakin to finally “seat” the rings under load by doing short 3rd gear highway pulls does the final step, most of the time the motor is broken in by the time you get to the highway to do the pulls.
You will not gain any kind of significant compression once the motor is initially heat cycled and put under load once.
“The first 50 miles (or so) are absolutely critical for the rings to seat, which can be achieved only by varying the load applied on the engine. Once the fresh crosshatching turns dull, there’s nothing that would make the rings seat later. The worst one can do is running the engine at continous speed and very low load (highway or idle). By the time one gets to the location where he does the WOT runs (while occassionally applying 1/2-3/4 open throttle during the trip), the engine is almost completely broken in. The WOT runs just finish up the break-in.” - Well known DSM engine builder (Well known engine builder in general)