Have tried this before to no such luck, though I do believe you that it has also worked out well.
IMO it's not a very organic form of play so even if it worked okay I wouldn't, personally, view it as a great solution; however, I would also admit that if it functions regularly it might be a good solution to other types of players. To me that sounds bothersome (and as said inorganic- to me), I'd prefer shouting in the zone once, waiting a bit, and then going with whatever was available (which in my experience is 1 to 2 people tops, and a painfully slow kill).
I would prefer if the system therefore did not require this, as I personally do not think anything should really require third party tools (I do have a LS for hunts). Nor do I think letting the thing reset and hoping it comes background during a limited play session is a good solution either.
Naturally for this situation I am not looking to work /with/ the system, I am hoping the system itself adjusts. Though I do, honestly, appreciate people trying to come up with those solutions- especially as there could be a chance I didn't think of or try them (in this case I am aware of failing causes them to become weaker, I just think that is a silly solution, and I did try yours and I believe circumstantially it might work out well.. I just don't think that either is what I'd be hoping for).
To me unless it's a world boss with the benefits of being a world boss that justifies consistent people presence (like Odin type stuff), that they should all be fairly dynamic in so much that they're fun to do with whatever the zone has available to do them with.
Some of this also coming from a recent sprint of GW2 playing as a local here suggested trying it, and I feel their systems regularly are approachable regardless of # and in the situations where it seems clear you should have more players they've done a better job ensuring players are interested in doing said content. So, in a sort of recap- in this situation I am not trying to work with the system.. I want the system to be, imo, better. As I feel I have seen better, in essence..
Though as I said, I do see the effort in solution you've given to me as genuine value and I do believe it might work on occasion.. I just don't think it should be like that (if they're world bosses then it makes, but their value demands consistent and relatively easy attendance.. their existence and welcoming cards almost self propagates itself).
Do you speak for the devs? Have you not seen them bother with things that seem to only affect a few? Does not seem you added much to the conversation with this post except speak for someone you shouldn't be.