This is already a known issue for some of our users
Non-ISO characters may not be mentionable via the AJAX Quick Reply due to the inherent limitation of AJAX technology.
The multiple word issue, along with the accidental email mistakes (user called Gmail.com being tagged when someone writes
qwerty@gmail.com etc) will be correctable by the Admin in the next update when we plan to optionally re-introduce the ; delimiter
The customer was made aware of this in his support thread.
Fillip