I found that the raid lacked feedback and was difficult to coordinate with other players.
Imagine how much more difficult the Shroud part 4 would be if you couldn't see anyone in the parties HP/SP (or Harry's).

The issues I encountered;
Some people did not respond in chat.
It is hard to tell the number, let alone classes, of people in each area.
There is no feedback (DM voice) that the raid is succeeding or failing.
Most of the time I cannot see the dragon (the star of the show).
Some used the raid to farm collectables (pulling the lever repeatedly to generate more spawns).
No way to know if there was 1 or 15 players in the raid, just that there was not ‘enough’.

Simple(?) modifications:
Include the number of players in the ‘not enough players, 16 recommended’ message. Include this info in the minute count down messages.

Make the arena a ‘cage’ (see-through walls) so I can watch the other groups fighting the dragon. I think that would be more dramatic and entertaining (as well as giving feedback as to how the raid was going).

Show all players ‘dots’ on the map (ie let me see how many are at each altar / lever).

Add messages when the dragon is damaging an altar (and when it teleports).