It's a very difficult feature. The area of TiniMCE editor is not accessible by simple code. It requires some callbacks or its own plugins, so there is no way to add autocompleting process with real-time AJAX requests in such a limited area. I'm not even talking about detecting of current cursor location to display the result near to that.

In other words, we don't plan it in the near future. And this will not be free if we find 2-3 month to work on such a small but very hard feature.

still no plans for auto-complete of usernames (for mentions) in the text editor?

Much appreciated!

We'll add it in the next version. BTW, the nickname is placed in the editor when you click the reply/quote button. Also, it exists under the post author avatars.

I still would love to hear from the developers and if they think they can add this in a future release, it doesn't seem to be too hard to get it done properly.

It will probably have to be redone every time the WPForo has an update, I guess, right?.

yes, or you use the > Theme Customization option

you can add it yourself if you want

open the profile_home.php
search for

<?php wpforo_fields( $fields ); ?>

at the end of the file

and paste this code above it

<div class="wpf-field wpf-field-type-text wpf-field-name-user_nicename  wpf-field-required " title="Nickname"><div class="wpf-label-wrap"><p class="wpf-label wpfcl-1"><i class="fas fa-link wpf-field-icon"></i> Nickname</p></div><div class="wpf-field-wrap">@<?php echo WPF()->current_object?></div></div>

or you can use > wpForo – User Custom Fields