These are all good points.
Let’s be fair, the meet-up facility has enhanced Zwift. It has enabled private social rides and races to be scheduled by groups of friends, and that has enhanced the rich set of options already on Zwift.
I’d see the suggestions offered as the logical next step. If meet-up organisers can schedule a meet-up as a race, then moving the start and end points to pens and finish banners, as in current public Zwift races would make a big difference and remove the random nature of the starts and having to use Strava segments to establish finishing times after the race completes.
There’s no need to make changes for social meet-ups. Spawning at the roadside as currently happens would be fine.