The X-Plane 11.1 beta is now in Release Candidate 2, meaning Laminar are getting close to releasing 11.1 as a non-beta product. I’ve only had one brief flight with it. My experience, like that of several others, is that there seems to be some issue between WorldTraffic 3 and 11.1rc2. My frame rates were highly variable — from the 4os down to the teens — vacillating back in forth in short order from good to awful. When I disabled WT3 my frames stabilized around their normal levels of 30+, and in fact, my impression is that my frames and smoothness both improved from rc1. I hope to take a longer flight today and we’ll see how things go. I have also read in the .ORG forums that WT3.1 may solve the issue, but for now I have the plugin disabled.