I have 20-30 different projects, each with roughly 5 members. That is total over 100 different members.
When I @-reply to a comment and write a name, very often I get 3-4 people with the same first name and it’s very easy to make the mistake of replying to the wrong person.
The @-search inside project or team conversations should limit the search to existing members of that project or team. Or at the very least, show them further down below some divider so it is clear that these are not members of the project.
Here’s a video demonstrating this problem: https://goo.gl/UNdX83