Before submitting your RF layout for PCB production, it is always advisable to make sure the critical RF paths traversing through the multi-layer PCB stackup will perform optimally. Now, selecting only what you want on your RF layout is possible. Analyze the EM quickly for loss, match and parasitic impedances. Instead of doing brute force full EM simulation on the whole PCB, efficient meshing and mesh domain optimization (MDO) refine the mesh around the selected layout fragments for fast interactive EM analysis. See how this is done in this tutorial video.