It would be helpful if buyers could filter out of their Themeforest search those themes with embedded 3rd Party products requiring a separate license for upgrades. This would be particularly valuable for those of us that want to use the new WordPress Editor (formerly Guttenberg). This also often applies, however, to sliders. It’s a security concern not to update these themes. It also, begs the question if you deactivate the plugin what problems might surface. Ouch!
I’m also interested in website optimization and these choices can be a poor choice for page rendering speeds.