Hi Damen,

Luke from the Product team here. Thanks for submitting this feature request and helping us to improve our product.

To summarize, I think we can support #1 for Facebook reels (reel_comment_history table). I've added this to our backlog for the team to investigate and prioritize, and I'll share updates here. I don't think the others are feasible given the current Facebook APIs. If you think I'm mistaken, please share links to the API documentation explaining how we could retrieve this data.

I've written more detailed responses to each of your points below.

Cheers,
Luke

For Facebook reels:

1. We use this endpoint to retrieve data for post_comment_history: https://developers.facebook.com/docs/graph-api/reference/v24.0/comment. We request data for each comment that we find when syncing POST_HISTORY. It looks like this endpoint can also be used to retrieve the reels' comments, so we could implement a REEL_COMMENT_HISTORY table similarly.
2. We use this endpoint to retrieve metrics for posts: /insights. That endpoint supports the metrics named post_activity_by_action_type*. We use those metrics to populate the lifetime_post_metrics_by_action_type. We use this endpoint to populate the lifetime_reel_metrics_by_action_type table: video/video_insights. Unfortunately, that endpoint doesn't include the equivalent by_action_type* metrics. 
3. (see above)

For Facebook posts:

1. To sync the lifetime_post_metrics_by_action_type table, we request data for the metric post_activity_by_action_type. The API returns the data as a collection of values. It looks like the snippet below. Therefore, it is up to Facebook to determine which action_types are returned. So if Saves are missing, it is because Facebook doesn't provide that data via the API. Unfortunately, we cannot support this request until they update the API to provide Saves as an action type.

"values": [
        {
          "value": {
            "share": 5,
            "like": 32,
            "comment": 1
          }
        }
      ]