Hi @jvandernet, yes the setting is global - you can submit a feature request to make it per team if that's something you would like, I can see how some people would want that.
1000 max users per team should be fine, we currently have 978 users signed up to our daily builds site, and we have customers with 1000 users signed up. Some of the modals (Manage Members, Direct Messages More menu) start to take a few seconds to load, but we're adding paging to those which should be in the next release (November 16th).