Selecting non-consecutive words
That's not possible at the moment, unfortunately.
With the split verbs in German, we don't have a way for you to save these properly. However, as long as you are aware of them, you should be fine. You can add a tag for "split verb" to help you identify these when you save the parts. You can sometimes capture both parts of the verb if you select them in a phrase (if the phrase isn't too long). You can add notes to help you remember. Keeping in mind that the majority of German words are not of this type.
And this is why an improvement to the notes function is badly needed at some point. At the moment, we can create as many notes as we want, there is no way to track them or review them, let alone remember the words to which they are attached. It would be great to be able to find them easily by clicking on an icon, just like for the playlist and then filtering them by lesson. The way notes are handled currently simply doesn't work.