Unfortunately it’s quite difficult for us to give a cover-all answer to the question of scaling. A lot of it depends on various factors of each game, and a lot is changing every month on our side as our tech changes. So I can’t really provide you an answer on how many entities you should expect to be able to support on various template sizes, it’s something you’ll have to test for yourself and optimize within your game.
For now, probably the biggest thing you can do is optimize your UnityWorkers. This is a nice presentation that touches on some of those topics, particularly around the 29 minute mark. Start by just running a single UnityWorker in your editor (with a launch config that doesn’t by default launch any managed workers), and use the Unity Profiler to work out where the most computation time is being spent.
For questions about how many workers you should be using, again the only thing I can say is you’ll have to test on your own. Factors such as entity density, how much entities move, and how evenly spread they are will all influence things. Beyond that, there isn’t much more I can add on this subject from what Callum already mentioned in the forum post you linked in your first post.
When it comes to optimizing various things for the Spatial bridge, we’ll hopefully be coming out with some more tools soon to profile this. But for now, things to think about are if you are ever sending more component updates than you need to (like is anything spamming component updates when they really don’t need to be so frequent), and check your usage of commands/queries which are fine to use in moderation but if frequent operations are constantly making use of them, you might be slowing things down on the bridge.