Hi Frank,
thanks for your review. As for the slow down you are talking about, do you mean on the frontend or on the backend? On the frontend there should be not noticeable impact on performance. On the backend the slowdown is due to the loading of the TinyMCE editor stuff, as it has to be necessarily loaded if you want to use it (this is not directly depending on the plugin itself).
The plugin also provides some hooks that allow devs to slightly gain performance by excluding some parts of the plugin fron being loaded. This is made at a cost of reduced compatibility with 3rd party plugins, but I think the gain would be not much noticeable.
Anyway if you’re experiencing an excessive slowdown, feel free to start a new topic in our support forum.