Could it be that you're just simply running more plugins at once now than you were before? Especially apemanzilla's Map Cacher plugin which was not functional in Riigged's release tends to have it's effect on the performance.
I suggest you delete the Map Cacher plugin (and the Auto Nexus plugin which is dependent on Map Cacher) and try what FPS you get. If your FPS increased you might have to play that way. Also, make sure that you don't have any unnecessary plugins active. If you don't need my Map Recorder you should delete it or move it out from the Plugins folder.
Other plugins you should disable are Live World Edit and Vault Chest Viewer.