There is a problem which is little hard to diagnose. When I switch level, I end up disposing a number of meshes and recreating some new ones. For some reason I found that doing this a couple of time the rendering performance keeps decreasing. Is it possible that meshes with mirror surfaces leave something behind? Is there any way to find out, where the performance is lost?
Another problem I see is that rotating a mesh using the gizmo shows this sudden interruptions of the otherwise smooth rotation. My suspicion is that also mirror textures may be generated on the fly, and after many megabytes the garbage collector needs to spend some time? If this is true, would it be possible to use a back-buffer scheme instead?
Could you create a repro ?
About the backbuffer we do support SSR for this 