There is a problem with this, since manual timing is considered by many users as “another review that Anki’s normal schedule does not fit, so I had to schedule in a custom way”. Therefore it is important to include this in the addon statistics as part of the regular reviews. Which is not the case in general scheduling of the entire collection because of FSRS which is not at all related to the normal order of reviews. You can simply set all these schedule in revlog as type 5