Autocomplete just the first name for @mentions in comments

When I mention someone in a comment, I often want to write something like:

"Sam, what kind of home brews do you planned for summer?"

But it actually autocompletes to the full name like:

"Sam Haldane, what kind of home brews..."

It would be ideal if we autocompleted to just the first name in comments. Since comments are a conversation, rarely do you mention or address someone by their full name. While lurking in the HipChat room for FedEx 18 (see screenshot below), I noticed they do this nicely.

If you look at their documentation, they describe how it works:

By default we will use someone's first name "@john". If there are two Johns, we will use their full name @"John Smith" to correctly identify them.