In the context of looking-up users with @-mentions, what are the pros and cons of starting showing results right after
@ has been typed or only after first letter (eg,
@e. The number of users can be anything from under ten to 200-300, and more.
Eg, should typing @ serve as discovery mechanism of this feature in the particular field? If not, what can be the affordance for that? (or is it even a problem for users to discover the feature? In this setting, many other fields do not have @-mentions capability when some do)
(I have seen What is the recommended minimum characters limit for auto-complete/filter? , but thought to ask more specifically of 0 or 1 characters after @)