I'm sorry, but I hate the change. Simulation distance 10 brought lag and everything lag brings with it. With the sim distance being on 10, that means players also have to spawnproof way bigger areas, wich I honestly definitly do not want to do. I'd like to be able to play, and not spend an entire month spawnproofing everything around my base. We joked around that from now on all bases will become skybases to not load mobs on the ground, but that's like the only viable option right now. I was perfectly happy with a sim distance of 4, I don't need more. If the realms would get a bigger sim distance, that should've been anounced weeks in advance. Think of all the mobfarms that are designed and spawnproofed for sim distance 4! All those need tweaking. I hope this change will get reversed, but as for now, I will stay of the realm as much as I can. Totally not playable.
You pointed out something I have missed indeed. By more testing I found however that the /fill ~~~ ~~~ lava_cauldron 6 places a full cauldron, but with dark lava, it doesn't shine. Do I make a new ticket, or do I update this one?