Thanks! They look quite slick and have a lot going on. Particularly the void dragons you sent my way.
Each would be more or less perfect for a single-monster encounter, as they are dense with fairly novel mechanics.
Many people think that the WotC statblocks are a bit too boring, but I consider them a good entry point for new GMs. This is clearly a nice way to up your game.
Cheers!
Most of that is being fixed by dilating the amount of damage output that players can output in 5e in a variety of changes in OneD&D.
My playtests have had really gripping & close fights, even with people optimizing their hearts out.